Cycorp Intent of Work:
Rapid Knowledge Formation (RKF) Technology for the DARPA Agent Markup Language (DAML)
Prepared by Stephen Reed
January 31, 2001
In the remainder of this fiscal year, Cycorp will provide three tools packaged as Semantic Web services integrated with other DAML contributors in the DAML Integrated Demonstration & Experiment, May and September releases:
1. Ontology Interpretation Tool: interprets a DAML ontology by
analyzing the lexical and semantic content of the ontology and of the web pages
marked-up by that ontology, in order to derive mappings from the local ontology
to semantic concepts in Cyc. We will
import into Cyc all the ONA experimental ontologies and as much of the instance
content as the experiments require.
Each ONA XML namespace will be modeled in a separate microtheory and the
DAML statements will be modeled using Cyc’s functional notation to associate a
resource (Cyc constant) with a namespace (Cyc microtheory). Imported DAML resources will be named
according to a convention that will clearly separate different meaning senses
of the same named resource. The suite
of Cyc NL parsers will produce a list of candidate matching concepts for each
resource based upon a parse of the resource tag name and taxonomic context. Once a set of initial Cyc mappings is
identified, the Interpretation Tool will perform a structural comparison and
correlation of the two ontological structures (the source DAML ontology and
target Cyc concepts) to discover additional mappings between uncorrelated terms
in the source ontology and additional target concepts in Cyc.
2. Ontology Elaboration Tool: uses Cyc's world knowledge and common
sense inference capabilities to derive additional semantic concepts closely
related to concepts represented in the DAML ontology and then suggest
additional terms for incorporation into the ontology. Once a concept has been
isolated, the Elaboration Tool will search for semantic connections in all
directions in the Cyc KB. This will
include lateral connections derived from terms sharing the same parents and/or
the same children in an ontological hierarchical graph. Elaborations will also
be made by commonsense inference. The
Cyc KB contains a great deal of general knowledge about human activities,
including business, military, educational, and recreational activities, which
it can use to infer related concepts.
These related concepts could then be suggested as additional
elaborations of the original source ontology.
3. Ontology Translation Tool: uses mappings between DAML ontologies
and Cyc knowledge base as a reference framework for deriving a translation
between the two DAML ontologies. The Ontology Translation Tool will produce a
translation between the two ontologies by deriving a translation function. This translation function will be the
composition of: the mappings from the original ontology to a set of equivalent
Cyc concepts (or compound expressions); the mappings from the translation
target to a set of equivalent Cyc concepts (or compound expressions); and the
mappings from the two sets of Cyc concepts (or expressions) to each other. The final product will be a mapping from the
source DAML ontology to the target DAML ontology that does not refer to the
intermediate reference ontology, Cyc.
In addition we will release an executable version of the Cyc Upper Ontology, which will be available for downloading from www.OpenCyc.org. Cycorp will, for the first time, provide the Cyc Inference Engine and a suite of tools for creating knowledge-based applications. OpenCyc 1.0 will be released and by year-end, this software will be integrated with the Semantic Web for DAML ontology import and deductive queries.
Separately developed ontologies will describe an Operational Net Assessment scenario in Afghanistan. Cycorp will help develop mappings for these user-developed, overlapping ontologies into the Cyc reference ontology. Once tied to the Cyc, the Elaboration Tool provides additional terms for use with the source ontologies. For example, once the user’s term for kind of vehicle is mapped to Cyc’s term #$TransportationDevice, then a wealth of more specific vehicle terms can be exported for use by other DAML project participants. Regarding the Extended Capabilities phase of the experiment, Cyc’s Ontology Translation tool will provide a translation service for users and other DAML project participants.
The Cyc KB
and associated applications are already well instrumented for RKF user
interactions. The DAML tools will be
instrumented in a similar fashion, measuring the performance of the ontology
interpretation, elaboration and translation processes. Cyc will conform to any end to end metrics
gathering standards mandated by the DAML experiment manager.
Once
end-users are empowered by DAML to create their own ontologies, there will be
an urgent need to interrelate those ontologies in a useful way. Cycorp's
services are targeted at the situation where the ontologies to be translated
are not richly specified, where a novice has quickly created a “light
weight” ontology, just to get started. In that case, it will be
necessary to interpret, elaborate, and fill-in intended meanings of the terms,
and then map those meanings to better-defined semantic structures. End-users want their locally created
semantics to be interpreted globally on the Semantic Web, and Cycorp’s DAML
services provide that capability.
End-users will appreciate the Cycorp’s lexical tools that employ the Cyc
KB to provide intelligent parsing and interpretation of noun phrases in DAML
tags; KB-based tools for automatically constituting complex concepts that are
implied by the DAML tags, but are not explicitly present.
Ontology
interpretation, translation, and elaboration services are widely useful as
middleware in an application, or as a member of an agent community, which is
performing tasks on behalf of end-users.
Many such tasks involve information stated in one ontology, but also
involve information stated in other ontologies – for example a Semantic Web
query stated in a manufacturing industry ontology, but whose answer set
contains information translated from a retailing industry ontology. Semantic Web search engines such as Haircut,
are highly motivated to employ Cycorp DAML services to expand the set of search
terms via translation and elaboration.
Ontology translation services can delegate to one another, portions of a
request for which they may not have the entire answer.
The ontology discovery ability of the Cycorp DAML services is important to users because ontologies will be continually evolving and new ones coming into existence. When a request to interpret a novel or updated ontology is received by Cycorp DAML services, the ontology (or only the relevant portions – if large) will be dynamically accessed and mapped to the Cyc reference ontology. Then the request will be processed. Subsequently, in an offline mode the novel ontology will be entirely mapped using time consuming methods if necessary. Then future requests involving this ontology will be processed without the delay of dynamic interpretation. End-users will require dynamic ontology discovery somewhere in the process chain or else the Semantic Web will grow stale and break.