Bunge's ontology describes the world in terms of things and properties of things. Wand and Weber developed the representation model based on Bunge's ontology to evaluate information systems concepts. This research empirically tests Wand and Weber's representation model in the context of entity-relationship diagrams (ER) diagrams. It examines whether associative object type indicators (a construct in some ER grammars) help users' understanding of the ER diagrams AOTIs do not correspond to any construct in Bunge's ontology, i.e., AOTIs are not things or properties of things. AOTIs function as both an object and a relationship between objects.
This research also examines the ontological clarity of another ER grammar, the weak entity types. Weak entities are existence dependent upon other entities. Some pragmatic ERD designers regard weak entities to have implementation benefits. Wand and Weber, however, view weak entities as redundant construct that are likely to impair users' understanding.
A laboratory experiment was performed with one hundred and four commerce and information systems students. Evidence from that experiment reveals that associative object type indicators (AOTIs) and mutual properties (ontologically clear constructs) are comparable constructs when used to replace relationships with attributes in ERDs. AOTIs do not obstruct users' understanding and, in fact, appear to represent a separate ontological construct of event. Weak entities are tested against AOTIs and mutual properties in ER diagrams. The use of weak entity types in ER diagrams is found to impair users' understanding and should be removed from future conceptual modeling tools.