Complex Knowledge Modelling with Functional Entity Relationship Diagrams

Modelling complex knowledge resources can be problematical as there is currently no formalism that can represent the nature of the data-seeking process at a conceptual level. We introduce the functional entity (FE), an encapsulated data resource that acts as a question-answering system, and identify nine different functional entities based on three main types of question-answer entailment: instance-dominant, valuedominant, and connection-dominant. We use functional entities to develop a generalisation of the EntityRelationship Diagram (ERD), the Functional-Entity Relationship Diagram (FERD), which can be used for high level conceptual modelling of heterogeneous knowledge systems. We further describe extensions to the FERD that permit modelling of resources that cannot be represented by traditional propositional form, and extensions relevant to large-scale documentation.