Organizing phenomena into classes is a pervasive human activity.
The ability to classify phenomena encountered in daily life in
useful ways is essential to human survival and adaptation. Not
surprisingly, then, classification-oriented activities are
widespread in the information systems field. Classes or entity types
play a central role in conceptual modeling for information systems
requirements analysis, as well as in the design of databases and
object-oriented software. Furthermore, classification is the primary
task in applications such as data mining and the development of
domain ontologies to support information sharing in semantic web
applications. However, despite the pervasiveness of classification,
little research has proposed well-grounded guidelines for
identifying, evaluating, and choosing classes when modeling a domain
or designing information systems artifacts. In this paper, we adopt
the cognitive notions of inference and economy to derive a set of
principles to guide effective and efficient classification.
We present a model for characterizing what may be
considered useful classes in a given context based on the inferences
that can be drawn from membership in a class. This foundation is
then used to suggest practical design rules for evaluating and
refining potential classes. We illustrate the use of the rules by
showing that applying them to a previously published example yields
meaningful changes. We then present an evaluation by a panel of
experts who compared the published and revised models. The
evaluation shows that following the rules leads to semantically
clearer models that are preferred by experts. The paper concludes by
outlining possible future research directions.
Keywords:
Conceptual modeling, classification principles, classes and types,
information modeling, design science