Many knowledge-acquisition tools are unsuitable for their tasks because they are adapted neither to the application domain, not to the requirements of individuals, such as developers and experts. Researchers in knowledge acquisition are experimenting with knowledge-acquisition tools custom tailored for specific domains [7][15]. Usually, such domain-oriented knowledge-acquisition tools are more useful than are general knowledge-acquisition tools, because custom-tailored tools can meet the requirements of the particular knowledge-acquisition situation.
Simultaneously, traditional knowledge engineering and expertise transfer is being replaced gradually by methodologies where developers assemble problem solvers for knowledge-based systems from reusable method components that accomplish subtasks [2][18]. In McDermott's [13] approach, developers use method-specific knowledge-acquisition tools to acquire the domain knowledge required by the methods. Method-oriented knowledge-acquisition tools, however, are not domain oriented per se; they must be adapted to specific domains and individuals.
Developers of knowledge-based systems wishing to use domain-oriented knowledge-acquisition tools face several barriers: It is difficult and laborious for developers of knowledge-based systems to adapt existing knowledge-acquisition tools, and to implement new domain-oriented knowledge-acquisition tools for new domains. Another barrier is that the investment of developing and maintaining domain-oriented tools cannot always be justified within the budget of a single application project. Many of these barriers can be eliminated by tools that enable developers to generate new domain-oriented knowledge-acquisition tools from high-level descriptions. Such metatools can simplify the task of developing domain-oriented knowledge-acquisition tools, and can reduce significantly the work required to implement these tools. Thus, metatools can make domain-oriented knowledge-acquisition tools feasible in situations where these tools could not be used previously. The knowledge-acquisition tools generated can then support the development of the target knowledge-based systems.
The design of metatools presents several epistemological and technical challenges. The way developers view knowledge acquisition affects the way that they design knowledge-acquisition tools. The developer's view of target knowledge-acquisition tools determines the appropriate specification strategy for target knowledge-acquisition tools in metatools. Automatic generation of such knowledge-acquisition tools requires a high-level description-or metaview-of the target tools [6]. For example, PROTÉGÉ-I/ [14] is a metatool that generates a domain-oriented knowledge-acquisition tool from an instantiation of a generic problem-solving method. The drawbacks of method-oriented metatools, such as PROTÉGÉ-I, are that the problem-solving method supported cannot be replaced easily, and that such metatools do not handle combined methods well.
We have formulated a metaview, the abstract-architecture view, for
specification of target knowledge-acquisition tools in metatools. The
abstract-architecture view is based on a decomposition of the major
functions in target knowledge-acquisition tools. In this approach,
developers instantiate and combine subcomponents into specifications of
target knowledge-acquisition tools, which are then used to instantiate
target tools. DOTS
is a metatool that implements the abstract-architecture view
[4]. DOTS allows developers to custom tailor
knowledge-acquisition tools for new domains with minimal effort. DOTS is
domain and method independent in the sense that it does not assume any
particular domain, or problem-solving method, for the knowledge-acquisition
tools it generates. DOTS assumes that the target knowledge-acquisition
tools are based on graphical knowledge editing; the target
knowledge-acquisition tools comprise several knowledge editors in which the
experts enter their knowledge actively according to their
conceptual model of the domain.