CATALOGEXPLORER

CATALOGEXPLORER is a system component of the integrated design environments based on the multifaceted architecture. CATALOGEXPLORER illustrates how a designer is supported in locating prestored design object in the example domains of plotting data in graphic programming [Fisc 91b].

The CATALOGEXPLORER augments the frame-based search technique provided by the HELGON system [Fisc 89] with the following mechanisms for retrieving from the catalog, design objects relevant to the task at hand:

ordering design examples by computed appropriateness values based on the current specification (retrieval from specification).
analyzing the current construction and retrieving similar examples from the catalog (retrieval from construction).

Retrieval from Specification. CATALOGEXPLORER provides a questionnaire type specification component that allows designers to specify requirements to their current task, at the level of a problem domain. These requirements relate to hidden features of a design. Hidden features are related to functions of the design rather than low-level or surface structure [Gero 90]. For retrieving design objects by hidden feature specifications, the system must have the domain knowledge for mapping those features onto the surface structure. Such domain knowledge is represented by:

specification-linking rules that link each subjective hidden feature specification item to a set of surface condition rules (in the integrated environment, this domain knowledge can be derived from the content of the argumentation base; see Figure 2).
a metric that computes an appropriateness value of each design example in the catalog in terms of a partial specification for dealing with trade-offs among contradictory specifications (the system then reorders the examples according to those computed values).

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For example, suppose a designer wants to create a program to plot the results of two persons playing one-on-one basketball. The designer first specifies some of the requirements using the specification sheet provided by CATALOGEXPLORER, such as ``need to illustrate the correlation of the two values'' (see Figure 2). The system uses domain knowledge in the form of a specification rule, ``illustrating correlation requires horizontal and vertical axes and a diagonal line.'' Using this knowledge, the system searches the stored example programs in the catalog which have those characteristics. The search yields as the most appropriate one, for instance, an example program that plots the results of two people playing squash.

Retrieval from Construction. For retrieving design examples relevant to a partial construction, one must deal with the issues of matching design examples in terms of surface features of a design, namely, at a structural level. Two domain-specific parsers analyze the design under construction by articulating types of design components being used at LISP structure level, and at graphics semantic level. Then the system retrieves design examples from the catalog each of which has the same set of types of design components in one of the two structure, according to a users' request.