What is Protégé-2000?
Protégé-2000 is an integrated software tool used by system developers and domain
experts to develop knowledge-based
systems. Applications developed with Protégé-2000 are used in
problem-solving and decision-making in a particular domain.
While our earlier Protégé/Win, like a classical database system, separately defined classes
of information (schema) and stored instances of these classes, Protégé-2000
makes it easier to work simultaneously with both classes and instances. Thus, a singular
instance can be used on the level of a class definition, and a class can be stored as an
instance. Similarly, slots, which earlier were employed only within classes, are
now elevated to the same level as classes. With this new knowledge model we also
facilitate conformance to the Open Knowledge
Base Connectivity (OKBC) protocol for accessing knowledge bases stored in
knowledge representation systems. Finally, applications on top of these
components are also executed within the integrated Protégé-2000 environment.
The Protégé-2000 tool accesses all of these parts through a uniform GUI (graphical
user interface) whose top-level consists of overlapping tabs for compact presentation of
the parts and for convenient co-editing between them. This "tabbed" top-level
design permits an integration of (1) the modeling of an ontology of
classes describing a particular subject, (2) the creation of a knowledge-acquisition
tool for collecting knowledge, (3) the entering of specific instances of
data and creation of a knowledge
base, and (4) the execution of applications. The ontology defines the set
of concepts and their relationships. The knowledge-acquisition tool is designed to be
domain-specific, allowing domain experts to easily and naturally enter their knowledge of
the area. The resulting knowledge base can then be used with a problem-solving
method to answer questions and solve problems regarding the domain.
Finally, an application
is the end product created when the knowledge base is used in solving an end-user problem
employing appropriate problem-solving, expert-system, or decision-support methods.
The main assumption of Protégé-2000 is that knowledge-based systems are usually very
expensive to build and maintain. For example, the expectation is that knowledge-based
system development is a team effort, including both developers and domain experts who may
have less familiarity with computer software. Protégé-2000 is designed to guide
developers and domain experts through the process of system development. Protégé-2000 is
designed to allow developers to reuse domain ontologies and problem-solving methods,
thereby shortening the time needed for development and program maintenance. Several
applications can use the same domain ontology to solve different problems, and the same
problem-solving method can be used with different ontologies. For more information about
building knowledge-based systems and the Protégé-2000 approach, see Planning a Protégé-2000 Project.
Protégé-2000 is currently being used in clinical medicine and the biomedical
sciences, although it can be used in any field where the concepts can be modeled as a
class hierarchy. Throughout this online guide, you will see examples of a newspaper domain
used to illustrate points of explanation; for more information about this running example,
see an overview of the Newspaper Example.
Next: Planning a Protégé-2000 Project