What is a Representation?

A representation is a (set of) data structure(s) which symbolizes, describes, or behaves as some aspect of the universe of discourse of the database or model. The modeled aspect need not be a concrete object, and can include multiple components: for convenience I will refer to the aspect as an entity. The representation should have the property of fidelity to the entity, but need not be a complete representation of all attributes of the entity. However, it is crucial that the representation include those attributes which are required for computations --- that is, be computationally sufficient.

As an example, consider your hand. One can represent this in the computer as the word ``hand'' (appropriate if listing appendages or describing the translation of the entire appendage through space, such as waving); a ``grasping device'' (appropriate if computing the results of the hand's action on a child's building blocks); ``four fingers and opposed thumb'' (appropriate if describing hand anatomy or complex hand motions such as piano playing); and so forth. For each of these representations one can devise related descriptions, specify when particular descriptions are to be used, or write rules which interconvert equivalent descriptions. Representations can be further grouped, or dissociated into component pieces, each with their own properties. The point is that there can be many allowed operations on representations, but each representation should be faithful and sufficient for the computational tasks it is intended to support.

Back to Klotho's home page.