The problem: Structural Heterogeneity

For example, 'date' might be represented as a single field in one database and as three separate fields corresponding to year, month, and day in another database.

The solution: Map to a common schema

Create a machine-processable domain-specific application profile for the field(s) based on the resource type to organize resources and alleviate differences in databases or other metadata schemas. Convert to metadata ontology to fully exploit the semantics.

The schema defines a common format for sharing date information. Each of the sources maps their date to the commonly required YYYY-MM-DD format provided by the W3CDTF - a profile based on ISO 8601.