Coverage of DDI 3.3 and GSIM — DDI 4.0 dev documentation

# Coverage of DDI 3.3 and GSIM

One of the initial requirements of DDI 4 was to cover all DDI 3.2 elements, and areas of GSIM that are relevant to DDI. A preliminary review of the classes in DDI 4, DDI 3.3, and GSIM was made by several members of the TC and is found in the document comparison.xlsx in the review package. Note that DDI 3.3 has been used for the listing as it has just completed a public review for publication. Only primary classes were reviewed. In DDI 4 this includes the published packages excluding Primitives, Regular Expressions, Enumerations, and Structured Data Types (198 classes). In DDI 3.3 only identifiable classes were used (231 classes). Relevant classes in GSIM (110 classes). Also, this is a preliminary review checking for conceptual similarity, that is that the two classes intend by definition to capture metadata about the same thing. It does not provide a detailed comparison to see if, for example, the DDI 4 class contains all the properties and relationships of the GSIM class.

In summary, DDI 4 covers 43% of the DDI 3.3 classes and 44% of the GSIM classes. The DDI 4 Prototype does not claim to be complete and this should be taken into consideration when looking at coverage. These are ball-park estimates of content coverage and help to understand the ability of DDI 4 to address the same content areas. For example, as a conceptual model GSIM may express a content area in fewer classes whereas DDI 4 is intended to implement the GSIM conceptual model.