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|United States Patent Application
Kahn, Robert E.
;   et al.
November 6, 2003
System for distributed task execution
Tasks can be done on a network of multiple computers interconnected by
communication links. At each of the computers, Knowbot programs may be
received and transmitted on the communication links, and may be stored
and created; and execution of the tasks associated with the Knowbot
programs may be advanced. Each Knowbot program includes a globally unique
identifier; navigation information defining a route through the network;
and information concerning a task to be done. Knowbot programs may
interact with each other and with other network resources. Authenticated
Knowbot service stations and Couriers may be used to protect data as well
as control its application in the network environment according to stated
terms and conditions.
Kahn, Robert E.; (McLean, VA)
; Cerf, Vinton G.; (Annandale, VA)
; Ely, David K.; (Oakton, VA)
FISH & RICHARDSON PC
225 FRANKLIN ST
Corporation for National Research Initiatives, a District of Columbia corporation
April 14, 2003|
|Current U.S. Class:
||1/1; 707/999.001 |
|Class at Publication:
What is claimed is:
1. A method for enabling tasks to be done on a network of multiple
computers interconnected by communication links, comprising, at each of
the computers receiving Knowbot programs on the communication links, each
Knowbot program including a globally unique identifier; navigation
information defining a route through the network; and information
concerning a task to be done, advancing the execution of the tasks
associated with the Knowbot programs, storing Knowbot programs, creating
Knowbot programs, and transmitting Knowbot programs on the communication
2. A method for enabling a computer on a network of multiple computers
interconnected by communication links to participate in a distributed
Knowbot service environment, comprising, at the computer receiving
Knowbot programs on the communication links, each Knowbot program
including a globally unique identifier; navigation information defining a
route through the network; and information concerning a task to be done,
advancing the execution of the tasks associated with the Knowbot
programs, storing Knowbot programs, creating Knowbot programs, and
transmitting Knowbot programs on the communication links.
3. A computer-based method for carrying out tasks comprising
interconnecting independent and heterogenous systems for the purpose of
carrying out the collaborative tasks.
4. The method of claim 1 or 2 further comprising interacting with a
participant at the computer to enable the participant to define the task
to be executed, and embedding information related to the defined task in
one of the Knowbot programs.
5. The method of claim 4 wherein the participant comprises a person.
6. The method of claim 4 wherein the participant comprises a process
running on a computer.
7. The method of claim 4 wherein the participant comprises a Knowbot
program running on a computer.
8. The method of claim 1 or 2 further comprising, at the computer,
interpreting task information contained in Knowbot programs.
9. The method of claim 1 or 2 wherein the step of advancing the execution
of tasks includes interacting with repositories of digital objects.
10. The method of claim 1 or 2 wherein the step of advancing the execution
of a task includes querying a database of information or other data.
11. The method of claim 1 or 2 wherein the information concerning a task
to be done includes interpretable or executable instructions.
12. The method of claim 1 or 2 wherein the step of advancing the execution
of a task includes applying stored expert knowledge.
13. The method of claim 1 or 2 wherein the Knowbot program also contains
data in the form of a digital object.
14. The method of claim 13 wherein the digital object includes protocol
15. The method of claim 1 or 2 wherein the step of advancing the execution
of a task includes protocol transformation.
16. The method of claim 1 or 2 wherein the step of advancing the execution
of a task includes providing a directory service identifying other
locations which provide services related to the task.
17. The method of claim 1 or 2 wherein the step of advancing the execution
of a task includes making a security determination.
18. The method of claim 1 or 2 wherein the step of advancing execution of
a task includes providing a "what's new" service.
19. The method of claim 1 or 2 wherein the step of advancing execution of
a task includes providing a "clipping" or "abstracting" service.
20. The method of claim 1 or 2 wherein the step of advancing execution of
a task includes providing a version control service for managing versions
of the Knowbot program.
21. The method of claim 1 or 2 wherein the step of advancing execution of
a task includes determining the structure of a Knowbot program and for
accessing its elements.
22. The method of claim 1 or 2 wherein the step of advancing execution of
a task includes responding to actions of a user by obtaining execution of
the task at another location without indicating to the user that the
execution occurred at the other location.
23. The method of claim 1 or 2 wherein the step of advancing execution of
a task includes creating a derivative work from an existing work.
24. The method of claim 1 or 2 wherein the step of advancing execution of
a task includes generating another Knowbot program.
25. The method of claim 1 or 2 wherein the step of advancing execution of
a task includes passing a message from a source Knowbot program to a
target Knowbot program at the same location or at a different location.
26. The method of claim 25 wherein the same message is passed to multiple
27. A method for executing a local query of a remote database via a
communication channel of a network where the local query complies with a
query protocol and the remote database is responsive to queries which
comply with a database protocol, comprising locally generating a Knowbot
program which is based on the local query and complies with a Knowbot
program protocol, sending the Knowbot program to the remote database via
the communication channel of the network, at the remote database,
responding to the Knowbot program by querying the database in accordance
with the database protocol, and returning the results of the query from
the remote database within a return Knowbot program which complies with
the Knowbot program protocol.
28. The method of claim 27 further comprising locally receiving the return
Knowbot program, and providing results to a user based on the results
contained within the return Knowbot program.
29. The method of claim 27 further comprising generating additional
Knowbot programs which are based on the local query and comply with the
Knowbot program protocol, sending each of the additional Knowbot programs
to another database, and at each of the other databases, responding to
the corresponding Knowbot programs by querying the other database, and
returning the results of the query from each of the other databases
within a return Knowbot program which complies with the Knowbot program
30. The method of claim 27 further comprising locally receiving the return
Knowbot programs, and processing the results contained within the return
Knowbot programs to provide a consistent presentation to a user.
31. The method of claim 30 wherein the consistent presentation to the user
is updated as additional return Knowbot programs are received.
32. The method of claim 30 wherein the processing includes removing
33. The method of claim 27 wherein the return Knowbot program is a
modified version of the original Knowbot program.
34. The method of claim 27 wherein the additional Knowbot programs are
generated locally and sent via communication channels of the network.
35. The method of claim 27 wherein additional Knowbot programs are sent
locally and where return Knowbot programs corresponding to the original
Knowbot program are received locally.
36. The method of claim 27 wherein the query protocol comprises a
displayed form, completed by a user.
37. The method of claim 27 wherein the Knowbot program protocol differs
from the query protocol and from the database protocol.
38. The method of claim 27 wherein the Knowbot program protocol comprises
the syntax of an executable interpretive programming language.
39. The method of claim 27 wherein the Knowbot program comprises an
executable interpretive programming language entry and a navigational
40. The method of claim 39 wherein the Knowbot program reaches the remote
database site by navigating the network, and wherein the navigational
portion of the message comprises information related to the navigating.
41. The method of claim 27 further comprising at the remote database site
sending a status Knowbot program indicating the status of execution of
42. The method of claim 27 further comprising at the remote database,
executing the Knowbot program to determine an appropriate database query,
storing the Knowbot program during the querying of the database and
controlling the querying of the database and the returning of the results
based on control information contained in the Knowbot program.
43. The method of claim 27 further comprising locally using a Knowbot
service station to create, send, receive, and delete Knowbot programs.
44. The method of claim 27 further comprising at the remote database site,
using a Knowbot service station to create, send, receive, control,
process, and delete Knowbot programs.
45. The method of claim 27 further comprising locally and automatically
selecting the remote database to which the Knowbot program will be sent
based on the local query.
46. The method of claim 27 wherein sending the Knowbot program includes
conforming the Knowbot program to an electronic mail protocol or a file
transfer protocol or other communication method on the network.
47. The method of claim 27 further comprising including in the Knowbot
program protocol transformation information.
48. The method of claim 1 or 2 wherein the Knowbot programs further
include authentication information.
49. The method of claim 1 or 2 wherein the Knowbot programs further
include scheduling information.
50. The method of claim 1 or 2 wherein the Knowbot programs further
include payment information.
51. The method of claim 1 or 2 wherein the Knowbot is persistent.
52. Apparatus for enabling tasks to be done on a network of multiple
computers interconnected by communication links, comprising a Knowbot
service environment including, at each of the computers on the network, a
Knowbot service station in the form of software running on a computer,
the service station providing services which include receiving Knowbot
programs on the communication links, each Knowbot program including a
globally unique identifier; navigation information defining a route
through the network; and information concerning a task to be done,
advancing the execution of the tasks associated with the Knowbot
programs, storing Knowbot programs, creating Knowbot programs, and
transmitting Knowbot programs on the communication links.
53. Apparatus for enabling a computer in a network of multiple computers
interconnected by communication links to participate in a distributed
Knowbot service environment, comprising a Knowbot service station in the
form of software running on a computer, the service station providing
services which include authenticating itself authenticating Knowbot
couriers received from other Knowbot service stations receiving Knowbot
programs on the communication links, each Knowbot program including a
globally unique identifier; navigation information defining a route
through the network; and information concerning a task to be done,
advancing the execution of the tasks associated with the Knowbot
programs, storing Knowbot programs, creating Knowbot programs, and
transmitting Knowbot programs on the communication links.
54. A method for executing a local query of a remote knowledge-based
system via a communication channel of a network where the local query
complies with a query protocol and the remote knowledge-based system is
responsive to queries which comply with a knowledge-based system
protocol, comprising locally generating a Knowbot program which is based
on the local query and complies with a Knowbot program protocol, sending
the Knowbot program to the remote knowledge-based system via the
communication channel of the network, at the remote knowledge-based
system, responding to the Knowbot program by querying the knowledge-based
system in accordance with the knowledge-based system protocol, and
returning the results of the query from the remote database within a
return Knowbot program which complies with the Knowbot program protocol.
55. A method for retrieving a digital object from a remote system, in
which the remote system embeds the object in a Knowbot program, the
Knowbot program is sent to the local system, where it is stored, the
local participant accesses the digital object via the Knowbot program,
the Knowbot program restricts access to portions of the object, requiring
additional authorization and/or payment for access to the object, and the
object's owner is notified as actions are performed on the object.
 This invention relates to distributed task execution.
GLOSSARY OF TERMS
 Below, for convenience, we set forth a short glossary of terms
which supplement explanations of certain terms used in the main text.
 "Network" is set of computers and a communication medium which
 "Network participant" is an entity that may require a task to be
done and has access to a distributed network.
 "Packet" is an elemental container for carrying data in a
distributed system; it typically includes addressing information used in
 "Protocol" is a set of commonly agreed rules which define the
structure, format, procedure and/or function that must be followed for
elements of a distributed system to communicate with each other.
 "Resource" is information or a service accessible at a location in
a distributed system.
 "Task" is something capable of being done using one or more
 "Digital object" generally means sequences of digits (containing
digital representations of virtually any kind of information) including
an associated unique identifier, called its "handle."
 "Repository" is a resource that stores digital objects and makes
them accessible over the network according to applicable terms and
 "Database" is an organized body of information structured so as to
analyze queries and furnish replies. A digital object may itself contain
a database or elements of a database.
 "Rights holder" is a person or entity which has legally enforceable
"rights" in a digital object.
 "Distributed system" may include a Knowbot system, as well as
components which are outside the Knowbot system, such as magnetic
diskettes, optical disks, and other large scale storage media, including
digital representations of data on paper.
 "Knowbot program" is an executable computer program, which may be
capable of moving from one location to another. It includes an
"instruction sequence" which defines a series of steps to perform a task
and also includes other data.
 "Courier" is used, on occasion, to refer to an instance of a
Knowbot program which is engaged in moving through a distributed system.
 "Knowbot system" is a system (including programs) for creating,
storing, and moving Knowbot programs among computers, executing the
programs, and moving to and storing the results as needed at destination
computers or the Network.
 "Knowbot service station" is software and/or hardware operating at
a location on a network and capable of actions such as generating,
storing, executing and deleting Knowbot programs.
 "Knowbot service environment" is a medium for handling Knowbot
programs and comprises a collection of Knowbot service stations. The
Knowbot system provides the service environment.
 "Knowbot framework" is a conceptual model which defines a currency
(Knowbot programs) for task execution and a medium (Knowbot service
environment) for handling the programs.
 "Notification authority" is a part of the Knowbot service
environment which stores information about operations performed by
 "Prospective Knowbot programs" are Knowbot programs received by a
Knowbot service station from a source outside the Knowbot service
 In the most basic sense, the invention concerns itself with a
system (we call it the Knowbot.RTM. system) for creating, storing and
moving programs among computers, executing the programs and moving to and
storing the results as needed at destination computers. While most or all
of the computers may be "online" and part of a general computer
networking environment, the concepts apply also to offline movement of
programs via other media such as magnetic diskettes, optical disks, and
other large scale storage media, including digital representations of
data on paper (such as bar coding). Moreover, the computers in the system
need not be simultaneously connected in an underlying network at all
times; this connectivity may come and go from time to time. The label
"system" generally implies some systematic regularity in the way these
programs are created and managed, the way they interact with each other,
the way they interact with stored information, and the way they interact
with external systems, including people and programs which are considered
to exist outside the scope of the definition of the programs and
computers which are part of the system.
 For purposes of explanation, we sometimes use the term
"Knowbot.RTM. system" (Knowbot.RTM. is a registered trademark of the
Corporation for National Research Intiatives) to refer to portions or all
of the system. The Knowbot.RTM. system has well-defined boundaries which
make it possible to distinguish the components that are part of the
system from components which are outside of it and which interact with it
only in ways defined by the system. What is inside the Knowbot system and
what is outside may together be called a distributed system. The parts
which are considered inside the system interact with other parts only in
prescribed ways. The rules which define proper behavior are, in effect,
specifications which determine how a component can be created and can
operate so as to always be considered a properly functioning component of
 The Knowbot.RTM. system is largely a software system whose
components are programs which operate in prescribed ways. Software
operates in a computer-based (hardware) environment and often in
association with software-based operating systems which are the basic
programs that create, allocate and manage resources on the hardware.
Underlying the basic design of the Knowbot.RTM. system is the assumption
that the computers on which the system is operated have operating systems
which provide functions needed by the Knowbot.RTM. system running "on top
of" the operating systems. Any operating system would be suitable if it
supports the embedding of the underlying computers in a data
communications (networking) environment and is capable of "time-sharing"
multiple programs running concurrently under the overall control of the
operating system. In addition, the programs (called Knowbot programs)
which are capable of moving between computers must contain sufficient
information to allow them to begin or resume execution as intended and
the computers must provide the necessary support environment such as
interpreters, schedulers, and storage. The Knowbot.RTM. system may be
implemented atop a wide variety of hardware and operating systems.
 It is also assumed that the computers that are part of the
Knowbot.RTM. system are at least intermittently connected to a common
communication network so that information can pass from one computer to
another from time to time, in accordance with the rules of behavior of
the Knowbot.RTM. system.
 The Knowbot.RTM. system links together into a common operating
environment many diverse and distinct systems and resources and serves as
an interconnection system between them. Information about one system or
its resources may be communicated to another system via the intermediary
mechanism, the Knowbot.RTM. system. The Knowbot.RTM. system may itself
enable tasks to be carried out distinct from the systems and resources
which participate. The Knowbots system may also facilitate these
participating systems and resources to carry out a given task.
 Below we discuss concepts which, when taken together, describe how
a collection of software, hardware, and communication facilities can be
organized to function as a Knowbot.RTM. system. Virtually all of the
concepts are based on software artifacts behaving in accordance with a
set of prescribed rules. These artifacts include "running programs" and
also "digital objects" that are stored away in "repositories" for later
access. The concepts of the invention generally are rooted in the
definition and behavior of software artifacts rather than on the
specifics of any particular hardware, communication network, or operating
system. However, if desired, portions or all of the software could be
replaced in certain instances with a system of integrated circuits (e.g.,
semiconductor chips) if and when the technology of very large scale
 Knowbot.RTM. programs are the basic software elements that execute
in a given machine. An instance of a Knowbot.RTM. program is a Courier,
the form taken by a Knowbot.RTM. program as it moves from one computer to
another within the system or when it interfaces with the external world.
Knowbot.RTM. programs can contain (carry) information (data) which can be
made manifest in a variety of ways. Provision is made in the Knowbot.RTM.
system for dealing with the arrival and departure of Knowbot.RTM.
programs, for the exchange of information between Knowbot.RTM. programs
and other Knowbot.RTM. programs, and for the interaction of Knowbot.RTM.
programs with other parts of the Knowbot.RTM. system including
information access subsystems called "repositories" and with external
subsystems, including people, by means of visible, audible, or other
 An important characteristic of Knowbot.RTM. programs is their
ability to protect data on behalf of rights holders, to control its
application in accordance with stated terms and conditions and to
interpret data, rendering it in multiple ways to be visible, audible or
otherwise palpable and in such a way as to permit human interactions to
influence the choice of renderings.
 Because the Knowbot.RTM. system has a software based
open-architecture interconnection structure, it is useful to discuss,
another highly successful software-based open-architecture
interconnection system known as the Internet. The Internet is a rapidly
growing, global "network of networks" which links millions of computers
and tens of thousands of networks together. The Internet is realized
through a set of minimum requirements for linking computers to each other
by way of a "packet switching" environment and through observing certain
format and procedural conventions ("protocols") that govern how and when
and in what form information is exchanged among the computers which are
part of the Internet.
 As seen in FIG. 1, the Internet 10 provides a communication
framework 12 for computer users located essentially anywhere in the
world. Any computer 14a may send digital information to any other user
14b by observing a commonly understood packet protocol 16 and a commonly
accepted addressing scheme 18. The packet protocol sets minimum rules for
the structure and handling of packets which carry the digital
information, including the address of the recipient. The addressing
scheme sets minimal rules for addressing assignments including prevention
of duplicate addresses. A computer that follows the packet protocol and
the addressing scheme may be relatively confident that a packet will
reach its destination and that the recipient will be able to access the
digital information carried in it. On the other hand, the Internet
framework makes essentially no attempt to define the physical
hardware/software network components 20 that are used to format,
transmit, receive, disassemble or assemble packets, and instead leaves
those matters to users, groups of users, and vendors. This has resulted
in an open, distributed market for implementation schemes and products.
 Because the hardware/software requirements of the packet protocol
are minimal, and essentially any digital information may be carried in
them, they provide a "currency" 22 for exchange of digital information
across a distributed network, just as paper checks provide a legal tender
for exchange of economic value. The unambiguous addressing scheme and
other aspects of the Internet framework in turn provide a universal
medium 24 for exchange of packets, just as the unambiguous transit codes
of the Federal Reserve clearinghouse provide a universal medium for
exchange of checks. But the Internet framework places no limits on the
physical manner in which users may create, transmit, receive, and use
packets, just as the clearinghouse system-places no restrictions
(provided paper size and other check protocol requirements are met) on
how checks are created, delivered, received, or used.
 The notion of disconnecting the medium and currency for exchange of
digital information on a widely distributed network (i.e., the framework)
from the physical implementation (suggested by the somewhat disjointed
representations 12 and 20 on FIG. 1) is a powerful one and has led to the
great success of the Internet, for it permits individuals and
non-commercial and commercial enterprises to participate and benefit from
the Internet without requiring central control of the implementation. At
the same time the Internet community is constantly working to enhance and
improve the principles embodied in the commonly accepted Internet
framework. This is achieved through a decentralized process in which
concepts may be generated from any source, tested, and if found broadly
useful, ultimately become part of the accepted framework. In this context
it is largely the quality of the proposed principles that generally
governs whether they become part of the framework and are widely adopted.
 Another powerful feature of the Internet framework and the physical
network on which it is implemented is its ability to coexist easily with
other frameworks of communication and other physical networks. The
Internet currently accommodates many different types of networks and
communications media; in principle almost any network or communications
media can become part of the Internet.
 Finally, the Internet framework is highly scalable which has
yielded a relatively easy expansion of the number of users worldwide.
 As seen in FIG. 2, in the invention, a new and more powerful
framework (called a Knowbot framework 28) is created not merely for
communicating digital information (as in the case of the Internet
framework), but for having tasks done on behalf of network participants
30a, 30b using resources available on a distributed system 32 (e.g., the
Internet, or another network). Within the phrase "network participants"
we include any entity that may require a task to be done, including
individuals with standalone personal computers and organizations, as well
as computers and other hardware and software in the network. By "task" we
mean anything that is capable of being done by resources on the network;
tasks may have a wide range of complexity, and typically they involve
more than merely a communication of digital information of the kind
effected by delivery of a simple Internet packet containing the digital
information; in particular, tasks often involve a process step to be
taken at a location that is remote from the location of the entity that
requires the task to be done. By "resources" we mean whatever is
available on the network that can contribute to the doing of a task; this
could include computer software, stored digital objects and a wide
variety of services.
 The Knowbot framework defines both a "currency" for having tasks of
any arbitrary complexity done, and a "medium" for handling the currency
as part of getting the tasks done. The currency is called Knowbot
programs. A Knowbot program is a mobile emissary of a network participant
which assists in executing a task to be done on behalf of the
participant. This task may be carried out locally in the user's system or
it may involve interactions with other systems and resources at other
locations both local and/or remote. The medium for handling Knowbot
programs is called a distributed Knowbot service environment or simply
the Knowbot service environment. The Knowbot service environment is
distributed as a potentially endless number and variety of what we call
Knowbot service stations (software and/or hardware) operating at places
on the network. The stations may generate, store, execute and delete
Knowbot programs and otherwise perform all allowed operations on Knowbot
programs as determined by the Knowbot program itself or by users
authorized to take or enable such actions. The Knowbot framework defines
a minimal set of rules 38 for the structure of Knowbot programs (for
example, the program must include some information related to the task to
be done) and a minimal set of rules 40 for the functions to be performed
within the Knowbot service environment (for example, that a typical
Knowbot service station be able to create, send, receive, monitor, and
delete Knowbot programs).
 Although we describe below some additional specific principles for
Knowbot programs and the service environment, in general it is
contemplated that enhancements to the Knowbot framework will be developed
in a similar manner as for the Internet framework, that is by a
combination of free market forces with respect to hardware and software
implementations, and by an open standards development process within the
Knowbot user community with respect to framework principles. Like the
Internet framework, the Knowbot framework is meant to coexist freely with
other techniques for doing tasks within a network and to be easily
 In general, in one aspect, the invention features enabling tasks to
be done on a network of multiple computers interconnected by
communication links. Some or all of these computers may also be internal
to the network. We use the term Courier, on occasion, to refer to a
Knowbot program that is being sent from one service station to another,
or is being exported (in some fashion) from the environment. At each of
the computers, Knowbot programs may be received and transmitted on the
communication links, and may be stored and created; and execution of the
tasks associated with the Knowbot programs may be advanced. Each Knowbot
program includes a globally unique identifier; navigation information
that may define a route through the network (when applicable); and
information concerning the task to be done. Knowbot programs which are
clones of each other will use the same basic identifier with a version
number or some other delimiter to distinguish among them.
 In general, in another aspect, the invention features enabling a
computer on a network of multiple computers interconnected by
communication links to participate in a distributed Knowbot service
environment by the steps recited above.
 Implementations of the invention may include one or more of the
 A participant at a computer (e.g., a person or a process or a
Knowbot program running on the computer) may define the task to be
executed. Information related to the defined task may be embedded in one
of the Knowbot programs. Task information contained in Knowbot programs
may be interpreted. The step of advancing the execution of tasks may
include: creating additional Knowbot programs, interacting with other
Knowbot programs, interacting with repositories of digital objects;
querying a database of information; applying stored expert knowledge;
protocol transformation; providing a directory service identifying other
locations which provide services related to the task; making a security
determination; providing a "what's new" service to identify newly
available information; providing a "clipping" service which extracts
information; providing a version control service for managing versions of
the Knowbot program; responding to actions of a user by obtaining
execution of the task at another location without necessarily indicating
to the user that the execution occurred at the other location; providing
a method for determining the structure of a Knowbot program (e.g., to
determine if a digital object is contained in the Knowbot program and to
access the element; creating a derivative work from an existing work;
generating a Knowbot program that contains another Knowbot program, or a
digital object, or other data; and passing a message from a source
Knowbot program to a target Knowbot program at a different location.
 The information concerning a task to be done may include
interpretable or executable instructions. The Knowbot program may include
data in the form of a digital object or a Knowbot program (a Knowbot
program may itself be a digital object). The digital object may include
protocol transformation information.
 In general, in another aspect, the invention features executing a
local query of a remote database (or a remote knowledge-based system) via
a communication channel of a network where the local query complies with
a query protocol and the remote database is responsive to queries which
comply with a database protocol. A Knowbot program is locally generated
based on the local query and in compliance with a Knowbot program
protocol. The Knowbot program is sent to the remote database via the
communication channel of the network. At the remote database, the Knowbot
program is serviced by querying the database in accordance with the
database protocol. The results of the query are returned from the remote
database within a return Knowbot program which complies with the Knowbot
 Implementations of the invention may include one or more of the
following features. The return Knowbot program may be received locally
and results may be provided to a user based on the results contained
within the return Knowbot program. Additional Knowbot programs may be
generated which are based on the local query and comply with the Knowbot
program protocol. Each of the additional Knowbot programs may work in
parallel on a given database or repository or may be sent to another
database. At each of the other databases, the corresponding Knowbot
programs may be serviced by querying the other database. The results of
the query from each of the other databases may be returned within a
return Knowbot program which complies with the Knowbot program protocol.
The results contained within the return Knowbot programs may be processed
locally to provide a consistent presentation to a user. The consistent
presentation to the user may be updated as additional return Knowbot
programs are received. The processing may include removing redundant
information. The return Knowbot program may be a modified version of the
original Knowbot program. Additional Knowbot programs may be generated
locally and sent via communication channels of the network. Knowbot
programs may be generated as well as received locally.
 The query protocol may include a displayable or machine
interpretable form, obtained from another program or completed by a user.
The Knowbot program protocol may differ from the query protocol and from
the database protocol. The Knowbot program protocol may include the
identity and syntax of an executable programming language. The Knowbot
program may include an executable programming language entry and a
navigational entry. The Knowbot program may reach the remote database
site by navigating the network, and the navigational portion of the
message may include information related to the navigating. The remote
database site may send a status Knowbot program indicating the status of
execution of the query in machine interpretable form and/or in natural
language (e.g., English). At the remote database, the Knowbot program may
be stored during the querying of the database, and the querying of the
database and the returning of the results may be controlled based on
control information contained in the Knowbot program. A Knowbot service
station may be used to create, send, receive, and delete Knowbot
programs. At the remote database site, a Knowbot service station may be
used to create, send, receive, control, process, and delete Knowbot
programs. The remote database to which the Knowbot program will be sent
is determined locally and automatically based oh the local query. Sending
the Knowbot program may include conforming the Knowbot program to an
electronic mail protocol or a file transfer protocol or other
communication method on the network. The Knowbot program protocol may
include transformation information.
 The Knowbot programs may include authentication information;
scheduling information; and terms and conditions information.
 Other advantages and features of the invention will become apparent
from the following description and from the claims.
 FIG. 1 is a block diagram of an Internet framework.
 FIG. 2 is a block diagram of a Knowbot framework.
 FIG. 3 is a block diagram of a Knowbot service environment.
 FIGS. 4A and 4B are block diagrams of Knowbot service stations.
 FIG. 5 is a block diagram of a transaction manager.
 FIG. 6 is a block diagram of a gateway.
 FIG. 7 is a diagram of the contents of a Knowbot program.
 FIGS. 8 and 9 are block diagrams of serial and parallel search
 FIG. 10 is a diagram of a Knowbot program.
 FIG. 11 is a block diagram of a Knowbot service environment.
 FIG. 3 depicts the Knowbot service environment 50 which provides an
extremely wide variety of functions 52a, 52b, . . . for handling Knowbot
programs 54a, 54b, . . . via an essentially unlimited number and variety
of Knowbot service stations 56a, 56b, . . . each in the form of hardware
and software running at a location on a distributed network. Examples of
Knowbot service stations would include software running on an individual
user's PC or laptop (service station 56a) or on a repository or database
server of a participant that is a supplier of digital objects (service
station 56e), or on a smart card or other personal digital equipment or
artifact, or on a telephone company central office switch (service
 As seen in FIG. 11 some of the most basic functions to be provided
by the Knowbot service environment include aggregation and presentation
services 170 which involve how information is collected and organized and
presented to end user participants and how requests for tasks to be
performed are elicited from end user participants 172; searching and
consolidation services 174 which involve how queries are presented to
repository participants 176 and other resources and how results are
consolidated for presentation to these resources; and
assurance/protection services 178 which validate the authenticity of
Knowbot programs and Knowbot service stations and their performance, and
that rights in digital objects will be effectively protected by these
programs and service stations in accordance with stated terms and
conditions. These services are discussed in more detail below.
 Knowbot Service Stations
 The Knowbot service station is analogous to an operating system but
does not allow participants to create arbitrary programs and files or to
run arbitrary programs, although it could allow selected users with
special system status great flexibility to manage the service station and
to upgrade its performance. In general, the service station creates
Knowbot programs in response to participant specifications and/or its own
internal requirements. Prospective Knowbot programs may also arrive from
external sources such as a user's PC that is not also a service station
and can be authenticated by a service station for use in the Knowbot
environment. Prospective Knowbot programs may also arrive on external
media such as CD-ROM. The service station also processes Knowbot programs
received from other service stations, and stores and manages Knowbot
programs within its own environment.
 As seen in FIG. 4, the functions performed at each service station
may generally fall into four major categories: i. basic administration 60
of Knowbot programs, include creating, sending, receiving,
authenticating, executing, storing, monitoring and deleting them; ii.
interaction 62 with a participant 63 to aid the participant in defining
tasks to be done and to provide the results of doing tasks in forms and
at times that are useful; iii. interaction 64 with a participant which is
serving as a resource 65 in getting a task done, including conveying
requests for information or actions in formats and at times that will be
understood by the resource and processing the information or results of
the actions; and iv. interacting with other service stations 66 and
interacting with hardware and software that is not part of the Knowbot
framework to enable a limited set of external, possibly untrusted actions
when appropriate and allowable.
 Knowbot programs 54e through 54p may pass from Knowbot service
station to Knowbot service station in the Knowbot service environment by
a variety of mechanisms, for example by being transported in Internet
packets. Knowbot programs 54q through 54t also may stay for periods of
time in a given Knowbot service station and in that sense the host
Knowbot service station may be thought of as a hot
el and/or processing
plant for Knowbot programs.
 Referring to FIG. 4B, the general structure of a generic Knowbot
service station includes storage 60 for Knowbot programs and Knowbot
program interpreters 62 for interpreting Knowbot programs written in
languages such as (but not limited to) PERL or PYTHON. A core Knowbot
operating system 68 provides basic key functions (discussed below) and
provides a Knowbot operating system application program interface (API)
64 which provides a predefined interface to and thus enables application
programs to be easily written to interact with the operating system. A
Knowbot operating system extensions API 66 provides an interface to
extensions 70. The extensions can include an almost limitless variety of
services and functions that supplement the basic functions of the
operating system, such as natural language processing.
 Simple Knowbot service stations need only be able to perform a
small set of basic functions and they may be implemented easily and in a
straightforward way in the form of a software program or VLSI chip. Other
more complex Knowbot service stations will have a variety of special
functions suitable to their locations in the network and to the entities
with which they are expected to interact.
 We turn to a discussion of a simple Knowbot service station with
minimum basic functionality. As shown in FIG. 5, the heart of the Knowbot
service station is the transaction manager 70 which acts as a kind of
traffic cop and status handler to supervise activities within the service
station. The transaction manager interacts with a Knowbot program
receiver 72 where Knowbot programs arrive at the service station, and
with a Knowbot program transmitter 74 where outgoing Knowbot programs
depart the service station. An input scheduler 76 keeps track of the
arrival of Knowbot programs and assures that they are scheduled for
handling in the service station at the appropriate time. An output
scheduler 78 similarly keeps track of Knowbot programs that are to be
sent out of the service station and assures that they are transmitted in
 Knowbot programs that arrive from an external source go directly to
the receiver. The receiver provides access control and evaluates whether
the incoming Knowbot program may properly enter the service station. If
so, it stores the program in a store 82. If not it may discard the
program or take some corrective action with respect to it. Knowbot
programs that are generated locally, e.g., from a resource at the same
location as the service station, are generated by or handled by a
translator or by a specifier and are passed to the transaction manager
for further disposition. The transaction manager may place the locally
generated program in a store for subsequent processing or transmission,
or it may hand it directly to the transmitter for immediate dispatch.
 The input and output schedulers determine what action to take with
respect to each entry in the Knowbot program store. Actions could include
performing steps called for by the program either immediately or at some
later time or periodically or after some other event has occurred. When
the time has come to perform such a processing step, the input scheduler
notifies the transaction manager. When the time comes to transmit a
program, the output scheduler notifies the transmitter.
 The transaction manager manages all transactions in the service
station and carries out periodic checks of status. It keeps track of
ongoing transactions and notifies other service stations of status and
error conditions (one way to provide the notice is by sending new Knowbot
programs to the other service stations). The transaction manager
maintains information about Knowbot programs created by the service
station, and deletes Knowbot programs when appropriate. If it deletes a
Knowbot program that originated in another service station it will
generally notify the other service station of such action.
 The transaction manager invokes the aid of an interpreter 84 to
execute a Knowbot program. This may occur, for example, to determine
whether a received Knowbot program is intended for a local user or for a
local repository or for another site. The interpreter "interprets" the
program (e.g., runs the Knowbot program) to determine what actions to
take. If intended for a local user, the results of the interpretation are
passed to a specifier which then communicates with the user. For example
the specifier could deal with presentation matters such as what images
can appear on a screen, or how many actions of a given type may be taken
on behalf of the user. This information may be derived from the Knowbot
 If intended for a local repository 86 (e.g., if the task
represented by the program is to access some information in the
repository), then the interpreted Knowbot program determines which
repository to access and plans the execution method (e.g., serial or
parallel, level of granularity, and how to order or combine the
information). It then passes the results of the interpretation along with
the program to one or more translators which then communicate with the
repository. The translators convert the requests that are represented by
the program to the language of the local repository. The local repository
may be able to execute the request directly. If appropriate for another
site then the transaction manager passes it to the transmitter for
dispatch over the network to the intended site, which will generally be
another service station but which may be a repository, a gateway, or some
resource outside of the Knowbot service environment.
 The repository search results would then be passed back through the
translator which would format it, place it in the store 82, and notify
the transaction manager. The transaction manager would then mark the
transaction finished and make an entry in the output scheduler module.
 The output scheduler provides a variety of return policies.
Normally, the results would be returned in the form of a program in which
case the transmitter 74 sends the program when and how indicated by the
output scheduler. In addition, the results could be communicated in
another medium (e.g., e-mail or file transfer) or made available in a
suitable "markup language" for delivery. The markup language provides a
self-describing form of information that denotes its substructure so that
another interpretation is possible downstream. The results may be
returned to the user or returned to a designated intermediate location
for storage or processing.
 A more complicated system 90, shown in FIG. 6, could be used by a
large provider of digital information stored in repositories 92a, 92b, .
. . to make services accessible to a variety of users. The users may wish
to submit materials for inclusion in the repositories or to access
information (digital objects, see below) held in the repositories. The
service provider would maintain a gateway that would include a number of
servers 94a, 94b, . . . at least some of which would include Knowbot
services stations 96a, 96b, . . . as well as other software associated
with the management of the repositories and the gateway. Each of the
servers could have an IP address. The servers may be connected to one or
more local area networks (LANs) 97, 98, which may also serve the
repositories and a set of routers 99a, 99b, . . . Each router would be
connected to a communication link, including, for example, dial-up,
wireless, X.25 link, or a connection to the Internet.
 Users wishing to make queries to the repositories could form
Knowbot programs which would first query an appropriate address server
102 to determine the IP address for the repository that could answer the
query, and then would proceed to the router 99b. Router 99b would route
the program to the appropriate one of the servers and the Knowbot service
station there would interact with the appropriate repository to complete
the query. Results could also be packaged in Knowbot programs and then
returned via the Internet.
 The Knowbot service stations in FIG. 6 interact with one another
for the purpose of coordinating search requests and other activities.
 Logical Structure And Operation of Knowbot Programs
 The logical structure of a Knowbot program is shown in FIG. 7 in
the form of fields of information that may be included to help guide the
program through the network and to provide instructions for its
operation. The exact order of the fields is not significant and fields
may be added or changed by the service stations as the Knowbot moves
through the Knowbot service environment. In storage, various means of
implementation are possible and many of the fields may be unnecessary and
may be omitted.
 The first field is a globally unique identifier 110 which
distinguishes this Knowbot program from every other Knowbot program
currently in existence in the Knowbot service environment. It may also be
useful in distinguishing Knowbot programs over long periods of time. A
portion of the identifier may be derived from the identity of the Knowbot
service station that created the Knowbot program. The identifier may be
used for retrieving a Knowbot program from storage or to refer to a
Knowbot program. If the unique identifier has semantics, the Knowbot
service station that created it will provide a type and version indicator
to make clear what the semantics are, or this information may be
contained in the system, time and date field mentioned below.
 The globally unique identifier allows the existence, location, and
activities of the Knowbot program to be controlled and determined with
certainty while it exists in the Knowbot service environment.
 The next (optional) field is authentication information 112 used to
assure the authenticity of the Knowbot program, in particular that it was
actually created by the environment that claims to have originated it.
Portions or all of the Knowbot program may also be encrypted if desired.
 The next field contains scheduling information 114 relating to when
and how often the task represented by the Knowbot program is to be done.
This may depend on cost and time constraints set forth in the field. This
field may also identify required status information (including error
information notifications). The scheduling information will generally
assume content specific information is located elsewhere in the program.
The scheduling information could indicate, for example, when the Knowbot
program executes functions, how long it should exist, and when and how it
should return status information. Specific examples of instructions for
starting a task include (a) "run this Knowbot program tomorrow at 2 pm on
repository X"; it might return a report on active Knowbot programs in the
repository; (b) "run this Knowbot program everyday at noon on repository
Y"; the results might be to say what has come in that is new that day;
(c) "wait until event Z (e.g., we know which currency we want to use) and
then run the Knowbot program using the results of that event," and (d)
"run this Knowbot program and if event W occurs (e.g., the value of this
stock ever goes below 15), take action Q (e.g., sell it), and if it goes
above 20, buy it." The Knowbot program 174 may also include other wake-up
criteria 182 and trigger conditions.
 The next field, navigational information 116, may capture either
information to control the future navigation of the program in the
Knowbot service environment and/or information about the history of the
navigational path taken by the program.
 The next field, terms and conditions 118, relates to areas such as
authorization of payment for tasks performed on behalf of the program or
terms and conditions for use. This information is protected by use of
public key encryption or some equivalent mechanism for authenticating
payments and other terms and conditions. The payment information can
indicate allowable credit limits, ensure authentication of payment, and
may be completely contained in the Knowbot program or may be associated
with digital cash payment systems or other electronic payment mechanisms.
 The next field, system, time, and date of creation 120, provides a
tracing mechanism in case the program is copied or a record of its
history is needed. A program embedded in another program will have its
own system, time, and date of creation. This field may also identify a
Knowbot program that can acquire the information.
 The next field, operation 122, typically would contain an
instruction sequence to be executed in conjunction with the contents of
the Knowbot program. Any language interpretable at the Knowbot service
station is permissible. The instruction sequence could even be a digital
representation of natural language (e.g., English) used in conjunction
with a natural language understanding program to interpret it. Simple
forms of the instruction sequence might be formatted search commands, or
access commands such as "access object with identifier X," or "search for
objects written by a specific named person." It may also identify a
process to be carried out, such as "execute me and pass the results to
the destination names in the results of the execution."
 The next field, path 124, will generally identify the most recent
service station to have handled the program, and it may also contain
information about the series of service stations that previously handled
the program along with the times when it was handled. In contrast to the
navigation field which may contain incomplete information about future as
well as previous trajectories, the path field is intended to yield the
definitive record of the path actually taken.
 The next field, description of data 126, will generally contain a
unique identifier (known as a handle) for data, the rights associated
with use of each part of data (see below), reporting requirements (if
any), and directions for using the instruction sequence. The directions
may be in the form of an executable program.
 The final field, data 128, contains one or more of the following:
 a. a digital object, by which we broadly mean sequences of digits
(e.g., binary digits or bits) and an associated unique identifier which
we call a "handle". A digital object may incorporate information or
material in which rights (e.g., copyright rights) or other rights or
interests are or may be claimed. There may also be rights associated with
the digital object itself. Thus digital objects may include digital
representations of conventional works (e.g., literary or pictorial), and
more broadly any digital material which is capable of producing desired
manifestations for a computer user. Thus, a digital object could include
programs and other data which may be based on or incorporate one or more
preexisting works. The digital object may be delivered over a network and
subsequently rendered on a computer screen (or other output device or
devices, e.g., a printer) in whole or in part. Digital objects may
include digital representations of audio, video or even 3-D scenes and
artifacts, as well as bit sequences that have the potential to be
rendered in many different ways and which renderings may be occurring for
the first time. By the notion of rights which are or may be claimed in a
digital object, we mean rights which exist under statute (e.g.,
copyright, patent, trade secret, trademark), or as a result of private
action (e.g., via secrecy, cooperative ventures, or negotiation).
 b. a sequence of bits (possibly with a data type)
 c. indirect references to other entities (such as digital objects)
 d. a set of the above
 e. a combination of the above (including sets)
 The contents description field allows the digital objects to be
separately identified and processed with full cognizance of the rights
and permissions associated with the contents. A digital object may itself
be a Knowbot program.
 Knowbot programs may communicate with each other as required to
carry out tasks. Among the means for such communication are the
following. 1. Multicast communication may be used to reach multiple other
Knowbot programs or when the location of a target Knowbot program is not
precisely known. 2. The source Knowbot program could send a message to a
target Knowbot program by routing it via the Knowbot service station that
created the target. 3. A mechanism could be used for direct communication
from one Knowbot program to another.
 In addition to a protocol or set of protocols defining how a
Knowbot program is to be sent and received, the system may include a
protocol or protocols defining how a message is to be sent and received.
In some cases it may be more effective to send messages rather than to
send the Knowbot programs themselves. E.g., a Knowbot program may arrive
at a Knowbot service station and wait for a message from another Knowbot
program before proceeding.
 Knowbot programs may interact with each other in a Knowbot service
station. Knowbot programs may be cloned in a Knowbot service station.
Each Knowbot program clone may operate independently of its parent and
siblings. Knowbot programs and their clones may coordinate their
activities and cooperate in performing a task. More generally any Knowbot
program may coordinate its work with any other Knowbot program, whether
or not they are clones.
 Knowbot programs may be persistent, that is they may be created
with the expectation that they will maintain a vigilant presence in the
Knowbot operating environment. Usually the persistent Knowbot program
will reside at a particular Knowbot service station, but there may also
be persistent Knowbot programs that are perpetually moving through the
Knowbot operating environment.
 A Knowbot program carrying a simple user query or system query may
produce a complex retrieval process or other distributed task execution.
Several repositories or databases may have to be interrogated to obtain
all the necessary components to satisfy the retrieval or other task
execution. (A repository may contain multiple databases or knowledge
bases). These components may be delivered to the user as a single
response or as multiple responses. In certain cases, the user may require
and the system may allow all or some of the components to be delivered
 A Knowbot program may carry out a complex task (possibly in
conjunction with other Knowbot programs, repositories, databases and/or
knowledge bases) that does not correspond to a query or a retrieval. For
example, it may make something happen in the network, or in a computer,
or a set of computers or the network such as activating programs, setting
parameters, or inserting software patches.
 Authentication and Security
 Knowbot programs and Knowbot service stations within the Knowbot
service environment may be designated as "qualified entities," that
provide certain assurances on system behavior although such assurances
may not be possible for all service stations. Various levels of assurance
may also be designated. For a service station, qualification amounts to
registering the existence of the service station within the Knowbot
service environment. The party applying for such registration would agree
not to modify (or otherwise tamper with) the service station except as
authorized. The service station could contain mechanisms to determine its
own integrity (e.g., if it has been altered or its operation otherwise
 Knowbot programs arriving at a qualified service station may be
allowed to be handled there without regard for the qualification of the
service station which originated the program, provided the cost of
execution is acceptable. For executions that are costly, electronic
payment may be required to be authorized or included. If digital objects
subject to rights (e.g., computer programs) or relating to rights (e.g.,
contracts or deeds) are requested for access, the Knowbot program may
only be allowed to be returned to qualified service stations at a certain
level of trust. A test may be made prior to performing the access to
determine if the source service station of the program is qualified or
not. Or, in a less restrictive scheme, the program may simply be limited
in what can be done with the digital object.
 For Knowbot programs, qualification may mean simply that a
qualified service station was the creator of the program, assigned it a
globally unique identifier, and maintains a copy of the Knowbot program
along with any associated information. When a Knowbot program is deleted,
a status message is returned to the service station that created it. This
message may be deferred in delivery if that station is not available.
Other mechanisms for notification in the event of long-lived Knowbot
programs and relatively short-lived stations involve transfer of
responsibility by notification to other stations.
 A Knowbot program may itself be viewed as a digital object when
stored in a repository maintained by or accessible to the service station
which created it. A Knowbot program may be deleted at any time by any
service station. The record of a Knowbot program may be deleted by the
service station that created it, when it is no longer deemed useful to
 Knowbot programs may request and/or receive digital objects which
may be subject to claims of confidentiality or proprietary rights while
resident in a given computer or while in transit over the network.
Traditional network security technology such as public key encryption may
be used for protection in transit and storage. The approach described
here will assist in protecting digital objects during computer
processing, subject to stated operations or types of usage. Certain
informational material will have the requirement to have this form of
protection while resident in the network environment. Only qualified
service stations will be trusted to have access to this material. Knowbot
programs resident in qualified service stations and in transit between
qualified service stations are deemed to be trusted. Knowbot programs in
all other environments and those not in transit between qualified service
stations are assumed not to be trusted entities. Sources of Knowbot
programs must be authenticated to insure that (in the return path) only
qualified-destinations can receive qualified Knowbot programs. Levels of
qualification as well as encryption may also be designated and maintained
with the system.
 It is possible to use service stations and Knowbot programs without
qualification, but there may be no guarantee made as to their ability to
protect intellectual property.
 A valid Knowbot program (e.g., one that has the required logical
structure to be a Knowbot program) may be produced by any participant
software that is capable of producing an appropriate Knowbot structure or
meeting appropriate interface constraints to other software which can
produce one. No constraints are placed on the participant side of the
interface in creating a Knowbot program. The structure may also be in the
form of an authorized or qualified Knowbot program if provided by or
validated by an authorized or qualified Knowbot service station. The task
description in a Knowbot program can be expressed in any language that
can be interpreted, e.g., PERL scripts, PYTHON, and others. A Knowbot
service station may support multiple language interpreters. A specific
language interpreter may interpret certain structural portions of a
Knowbot program expressed in another language. In any case, a qualified
Knowbot program is only produced by a qualified Knowbot service station.
 By operating within a qualified service station, qualified Knowbot
programs are able to protect intellectual property in the Knowbot service
environment. Requests for information from unqualified programs will only
be fulfilled if the rights owners are willing to have their intellectual
property sent to unqualified service stations. There is no technical
restriction assumed to be placed on communication between unqualified
programs or the type of activity that might take place. Thus, any
information sent outside the qualified service station is subject to no
further guarantees from a qualified service station. Such action will
normally only be taken with the permission of the rights holder, if any.
Such permission may be indicated in the terms and conditions field.
Within the qualified service stations, however, rights and claims to
rights will continue to be protected.
 Record Keeping
 Each Knowbot program may contain, name, or point to none or one or
more digital objects. These will generally be subject to rights and
interests. Enough information is contained in a program to determine
which operations are allowed to be performed on each digital object and
the reporting that is required.
 Knowbot programs may produce retrievals from repositories,
operations upon themselves, interactions between programs, and deposits
into repositories. They may also be sent to qualified service stations.
In certain cases, where permitted by the rights holders, they may also be
sent to unqualified service stations.
 Each service station will keep track of operations performed on
each Knowbot program and will report back electronically as appropriate
(on usage according to the terms and conditions contained in the Knowbot
program) to a "notification authority," a logically distributed system
which is a key part of the Knowbot service environment or the rights
administration process of the rights holder. In some cases, notification
will be required each time a significant event or operation takes place
(e.g. executing a task on behalf of a Knowbot program which is based on
or incorporates information or material subject to rights). In other
cases, only periodic reporting will be required (e.g. monthly or every N
 If the notification authority's system goes off the network,
reporting requirements may be suspended, although local collection of
information for later reporting may still be required. Alternately, users
may be restricted from executing on behalf of the Knowbot programs under
such circumstances if the requested level of notification is not
possible. For example, certain applications may be time dependent and
depend on replenishment of "electronic permits" over the network from the
collection system (or more generally from a rights management system) in
order to continue usage.
 If a service station goes off the network and is not reconnected
within a specified period of time, all Knowbot programs which must
provide notification reporting may be rendered inoperable (for example
due to service station storage constraints) until the service station is
connected again and the notification system has been updated.
Alternately, for this case a service station may be authorized by a
rightsholder to remove any restrictions on activation of or reporting
about Knowbot programs that contain any of his material. The Knowbot
program could also be made to delete any reports that have been collected
while disconnected from the collection station, if they are not needed.
EXAMPLES OF APPLICATIONS
 The Knowbot framework enables a virtually endless variety of
applications which make use of information stored in and services
available at one or more computers in a network. The applications may
perform complex tasks not limited to the typical simple access request
for information on a single computer (e.g., at what network address
should I send E-mail to Jim Daniels, or what is the public key for Jim
Daniels?) or a single command to a remote server (e.g., issue a one-way
plane ticket from Washington, DC, to San Diego for Jim Daniels anytime on
Mar. 3, 1998). Instead the Knowbot framework allows a participant to seek
information or to accomplish tasks which may need to be accumulated from
or performed at multiple computers according to a strategy not known in
advance and in which later steps in the strategy depend on the results of
earlier steps in the strategy. The framework enables all of this to be
accomplished transparently (or with notification, if requested) to the
 One broad class of applications involves responding to a single
participant request for information which can only be obtained by
accessing separate databases located at different remote locations on a
network and assembling the information for coherent presentation to a
 In a specific example, FIG. 8, assuming there is no central
registry for obtaining Internet addresses, if a user at a local computer
130 wants the Internet address of another user, the first user would
enter a single request 130 identifying the other user. The local Knowbot
service station 138 would interpret the request, create a corresponding
Knowbot program and send it to a series of other computers 132, 134, 136,
each of which has its own Knowbot service station, and each of which is
known to maintain a user address directory. (This may be known in advance
if the local computer's service station has a table of the addresses of
computers which maintain such directories; otherwise, the service station
must get it by sending a Knowbot program first to a computer known to
have such a table.) Each of the directories 138, 140, 142 on computers
132, 134, 136 is likely to have its own naming and addressing
conventions. The service station at computer 130 may be set up so that
the user's query is phrased in accordance with a common protocol, and the
service stations at the other computers may include conversion routines
that convert the incoming request at each directory from the common
protocol to a form that permits direct querying of that directory. The
result of the query may then be inserted into the Knowbot program, which
then proceeds to the next directory. Each of the service stations serves
temporarily as a "
hotel" for the Knowbot program during the time when the
query is being executed there.
 When the Knowbot program has completed its rounds and returns to
computer 130 carrying the results of the multiple accesses, an extension
or enhancement of the local service station may convert back from the
common protocol to a format useful for local display of the information.
The local service station enhancement may also organize the results in
accordance with the user's preferences, before displaying them. For
example the user may have asked for a display in reverse chronological
order based on the most recent update of the entry, with the display
showing the database or repository where each entry was found.
 Having the Knowbot program perform this searching in round robin
fashion as in FIG. 8 (i.e., serially, thus decentralizing task
management) may take an unacceptably long period of time. An alternative
scheme involves sending several Knowbot programs essentially
simultaneously to the computers 132, 134, 136 and having them return
independently to the originating computer 130 (as shown in dashed lines
in FIG. 8) hopefully within a designated time-out period. This parallel
approach to accumulating information (i.e., centralized task management)
is especially important in reducing delay where the number of computers
to be visited is large (as it often will be).
 In another example, a user at a local computer may want to
determine the current price of particular foreign long-term bonds in US
dollars; the user may be unaware that this simple query actually requires
fetching the price in a foreign currency and converting it to US dollars
based on the current exchange rate. An extension or enhancement to the
local Knowbot service station may provide a user interface that allows
the user simply to phrase the problem to be answered, without naming the
pieces of information that must be fetched. The service station would
send one or more Knowbot programs to the proper remote nodes to fetch the
needed information. Once the information has been returned, the local
service station enhancement would use the current price and the
conversion rate to determine the answer and would deliver the answer (but
not necessarily the pieces of information) to the user. Since currency
conversion may occur at multiple exchanges, the user will get an answer
that is based on one (or more if desired) of the close but slightly
differing exchange rates or upon an average of rates from several
 In this example, we assumed that the user would be able to
formulate the problem to be solved, requiring only that the service
station use Knowbot programs to get the missing pieces of information and
then perform the computation. But suppose the user is only able to
articulate the problem in non-mathematically precise words and needs help
in converting the problem to a mathematical form and then solving it. The
user could enter his query in words, e.g., "What is the likelihood of
dollar sales for PCMCIA modem
s world-wide reaching $50 million in 1999?"
As seen in FIG. 9, the local computer's service station extension or
enhancement might first send a Knowbot program 151 to a remote service
station 152 at a location which has an expert-system 153 which contains
knowledge on how to estimate dollar sales of a product. The program might
carry a query along the lines of "What information do I need to know to
answer the following question: . . . ?" The expert system 153 may provide
the answer "Sales of the product in the past five years in the United
States, population of the United States as a percentage of world
population, and an estimate of the viability of the product in the face
of specific new technology." Assuming that the answer also gave addresses
of computers where the answers could be found (if not, the Knowbot
program would have to make visits to other computers to get that
information), the Knowbot program could then, with the aid of the service
station 152 spawn three new Knowbot programs 160, 162, 164 addressed to
three other computers 154, 156, 158 where the information is located. The
programs could be sent in parallel or a single program could be sent
serially. When the information is returned to service station 152
embedded in Knowbot programs 166, 168, 170, the original Knowbot program,
which may have been waiting at service station 154, may then cause the
three spawned programs to be deleted, and carry the results back to the
service station 150. The answer then could be generated and displayed.
 The service stations and Knowbot programs offer a rich framework
for controlling access to, use of, and compensation for digital objects
located at computers in a way which should encourage creators of and
other owners of rights in digital objects to make them available on the
network. By the notion of rights in a digital object, we mean rights
which exist under statute (e.g., copyright, patent, trade secret,
trademark), or as a result of private action (e.g., via secrecy,
cooperative ventures, or negotiation). Additional information concerning
repositories and control of digital objects is set forth in U.S. patent
application Ser. No. 08/142,161, filed Oct. 22, 1993, assigned to the
same assignee as this application, and incorporated by reference.
 A creator or owner of a digital object typically will want to be
able to control its use, reproduction, and accesses or performances, and
to be compensated for permitting those acts. For example, the owner of a
digital object whose data will manifest an image of George Washington
when interpreted by the receiver ("the George Washington data") 150 may
wish to charge less for a single use by a high school teacher than for
multiple uses by an advertising agency. To prevent the George Washington
data sent to the high school from being delivered to an unauthorized
third party, the Knowbot program used to carry an encrypted version of
the data on the network to the high school may also carry instructions
which, by interaction with the service station at the high school,
restrict access to the encrypted data to a specified computer and for use
with a specified registered copy of software at the high school.
 A creator or owner of a digital object also may wish to receive
reports on the uses, reproductions, and disseminations of its digital
objects, for example to seek payment or to cross-check payments that have
been received, or may merely wish to keep statistical information.
Knowbot programs may interact with the service station to provide this
service. In the George Washington data example, the owner may attach a
price schedule to the data which is carried by the Knowbot program that
is transporting it. The owner's Knowbot program may then, through
interaction with the service station at the user's site, negotiate, in
effect, with the purchasing computer with respect to a potential use for
the data. Or the price may have been predetermined. If the customer
agrees to a price, the owner's Knowbot program may permit access to the
object and then report the new "purchase" to the owner.
 The Knowbot program may use payment mechanisms already available on
the network automatically to collect payment for ongoing uses of the
digital object, according to a payment schedule that is either attached
to the digital object (Knowbot programs could be stored in a repository
with the digital object and the payment schedule packaged together) or
available elsewhere on the network. The owner of the George Washington
data 150 could maintain a bank account or funds account on the network.
The owner's Knowbot program could then conduct complete transactions with
purchasers of the object, ending with the transfer of funds from the
purchasers to the owners account on the network. The funds may take the
form of direct money transfers, digital cash, or credit card (such as
Visa or Mastercard) charges. In addition, other trusted authorization
servers could be used.
 The Knowbot program also could serve to control the use of a
digital object as part of a derivative work being generated by a user.
For example, the owner of the George Washington data could choose to
permit a reduced resolution version of the representation to be altered
for use in an on-line work about American history or a black and white
representation to be created from a colored version. A Knowbot program
could control access to the derivative work in the network, and could
report the number of accesses back to the owner. The owner could arrange
for the Knowbot program to take care of the payment transaction
automatically, as discussed above. In general, Knowbot programs could
retain information about the derivation trail of a derivative work.
 The Knowbot program itself may be involved in the creation of
derivative works based on existing works. This could involve the Knowbot
program adding new material to an existing work recasting an existing
 Just as the owner of a digital object wants to be paid for its use,
the user of digital objects wants to make sure he does not unknowingly
run up an intolerably high bill for accesses to digital objects. A
Knowbot program sent out to accumulate information on a topic could
automatically and without the sender's knowledge run up fees for
accessing digital objects at many remote locations in the network. For
example, a user might launch a query that would have the inadvertent
effect of seeking out and purchasing every available piece of information
on sailboats. A service module could be included in the service station
located at the requester's site which would prevent Knowbot programs
launched by that service station from accumulating charges greater than
some amount decided by the user via a screen-displayed form or it could
help select the best set of sites to access for a given budget.
 Another use for Knowbot programs could be in giving access to a
combination of clinical data for a particular patient and a medical
database. In a specific example, the Knowbot program would retrieve the
patient's temperature and related information from the network and
compare the temperature to applicable norms as described in the medical
database. If the Knowbot program determines that the patient has a fever,
the Knowbot program could access treatment information in the medical
database and then find an appropriate treatment schedule all on the same
 Knowbot programs may be used for network support and assistance
jobs. For example, a service station may serve as a layer of protection
between a database and the information consumer, to prevent overloading
of the database and to prevent intrusions that may damage the database.
Knowbot programs could also help diagnose problems in the network.
Knowbot programs may gather traffic, use, and system status information
and then make reports on and also repairs to the network based on this
 A database gatekeeper for Knowbot program inquiries would receive
Knowbot inquiries in a buffer store and then apply the inquiries to the
database at regular intervals to help prevent overloading the system
containing the database. In addition, the gatekeeper is designed to
provide a layer of protection for the database against intrusions that
may damage the database during handling of inquiries.
 Existing database equipment and storage devices may be updated with
new service station software and possibly new hardware to provide a
standard Knowbot program interface to the storage devices without losing
the value of existing equipment and data.
 A Knowbot program sent from a service station may include or
indirectly access a knowledge-based or expert system with knowledge
inputted using rules, frames, and scripts and possibly natural language.
 A Knowbot program may be used for administrative tasks such as
managing library resources, organizing resources, characterizing data
streams, coordinating among digital objects, determining structure of
Knowbot programs, digital objects and other data, and building links
among digital objects. A Knowbot program may be involved in managing
interaction with distributed resources, including assisting in soliciting
and managing bids. For example, the Knowbot program may ask the same
question of a number of bidders and then organize the answers for the
user. In another example, the user may authorize the Knowbot program to
automatically select a bidder using a cost-to-quality ratio or similar
formula. If the user is not especially concerned with quality, the
Knowbot program automatically selects the lowest bid for the user.
Alternatively, the Knowbot program is authorized to take the time of
delivery into account.
 A Knowbot program could be used to protect sensitive or
confidential information. In this case, the terms and conditions might be
based on the identity of the user and his need to know.
 A Knowbot program may be involved in a smart directory service. The
Knowbot program would take the user's profile and seek out and organize
directory information for the user, updating the information as the
user's profile changes. For example, if the user's profile reflects the
user's interest in being aware of all Italian restaurants within a
five-minute drive of the user's present location, the Knowbot program
would update the user's directory entries for Italian restaurants as the
user's location changes.
 Knowbot service stations could include third-party value-added
service providers that facilitate the transfer of information from
information providers to information consumers. These third-party
providers could be clearinghouses, catalogers, and routers; or "what's
new" providers of information about new services and resources available
on the network; or a reference information server that provides
identification information about digital objects and other information in
the network; or a browsing server that would help a user or a Knowbot
program to find information based on only broad criteria about the
desired information; or a query adviser that would help a Knowbot program
in developing proper queries for representing a user's original search
question; or a database rating service.
 Service providers could maintain sophisticated computer programs,
such as writing quality analyzers, oil exploration analyzers, and patent
application analyzers, and use those works to provide value-added
services on the network.
 A Knowbot program created by an information provider could carry
information from a repository, and then return to the information
provider a confirmation of delivery.
 As shown in FIG. 10, Knowbot programs may be nested with a first
Knowbot program 160 containing a second Knowbot program 162 which in turn
holds retrieved information 164. The second Knowbot program helps the
information provider with access control (e.g., authorized execution,
replication protection) because it can keep track of and control access
(e.g., execution, replication) of the retrieved information. Also, the
second Knowbot program may help with intellectual property protection
because it can keep track of and limit access to retrieved information
depending on the authorization of the party seeking access.
 A Knowbot program may have as its mission the elimination of
corrupted or garbage data or information from a system or network. It
could do this by traveling from service station to service station at
each of which it could examine programs located there for corrupt formats
or lapsed lifetimes.
 A Knowbot program could provide protocol conversion or other
interpretation services between heterogeneous systems and applications.
The intervening network need take no part in the conversion process.
 An information provider such as a university which wants to make
its journal articles accessible on a network could set up a Knowbot
value-added service module as part of a service station. The module is
accessed over the network (in natural language or some structured
classification scheme) and the input received is used to guide a search
of the repository for the digital representation of the articles,
identify the relevant data to the potential consumer Knowbot program, and
negotiate a sale. The consumer Knowbot program either has the capability
of agreeing to terms and conditions or requiring that the data be sent to
the user who then makes the decision about whether to purchase.
 In another application, a Knowbot program visits a story board
generating program and then stores the requested story board. Next, the
Knowbot program visits a music-generating program, a graphics-generating
program, a text-generating program, and a video-generating program. The
Knowbot program that returns to the user contains a computer program
(sometimes called a multimedia work) or a digital representation of the
components of the work that incorporates digital representations of the
automatically generated components. A similar process could be used for
producing other digital objects.
 In another example, a Knowbot program acts on behalf of a user who
wants to buy a bed for her bedroom and a table for her living room. The
user's local service station has access to knowledge about the kinds of
questions to ask of the user and generally where to find information. The
service station drives an interactive program that obtains dimension
information from the user, and also knows that it needs to find out who
manufactures beds and tables. The service station sends a Knowbot program
to learn about manufacturers and receives multiple answers.
 In another illustration, multiple Knowbot programs contain
instructions on what to do in reaction to the actions of other programs.
This could be used in a war games simulation, where a Knowbot program
would be analogous to a tank that has distinct properties and
capabilities. Here the Knowbot program is an active ongoing entity whose
existence continues throughout the simulation.
 Such a scheme could be used in assisting the modeling of new
complex systems such as a new airplane. Computations for modeling each
part of the airplane, such as a wing, could be done separately and then
the interactions of the parts could be managed through Knowbot programs.
 In the case of database queries, a Knowbot program could operate by
taking a request for information from a form filled out by the user and
then, for each database to be searched, converting the request with the
aid of a specialized thesaurus in the service station, into the proper
query format for that database.
 Alternatively, each database could be associated with a service
station having a standard Knowbot interface capable of receiving and
understanding standard Knowbot program requests for information. The
Knowbot program need only convert user requests into the standard format
before making queries of a database. Using a standard format helps in
maintaining the quality and integrity of the information retrieval
capability. It also enables a data carrier entity to do business in
information transfer, such as connecting a seeker of information with a
source of information, without having to become involved in format
conversion activities. The carrier entity is thus enabled to add value in
addition to simply delivering the data, such as automatically connecting
a consumer of a data service with the most cost-effective provider of the
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