The part-of construct is a fundamental element of many conceptual
modeling grammars that is used to associate one thing (a component)
with another thing (a composite). Substantive theoretical issues
surrounding the part-of construct remain to be resolved, however.
For instance, contrary to widespread claims, some researchers now
argue the relationship between components and composites is not
always transitive. Moreover, how the part-of construct should be
represented in a conceptual schema diagram remains a contentious
issue. Some analysts argue composites should be represented as a
relationship or association. Others argue they should be represented
as an entity. In this paper we use an ontological theory to support
our arguments that composites should be represented as entities and
not relationships or associations. We also describe an experiment
that we undertook to test whether representing composites as
relationships or entities enables users to understand a domain
better. Our results support our arguments that using entities to
represent composites enables users to better understand a domain.
Keywords:
Conceptual modeling, information systems development, ontology,
part-of relations, aggregation, composition, meronymic relations,
mereology, mereotopology