IVOA Provenance Datamodel

A Parameter allows to list the values read by an activity to parametrize its execution. Each Parameter is identified by its name and can be queried. A parameter is a specific class.  In contrary to ValueEntity it does not hold all the relations an Entity may have :

• no Agent link,
• no hadMember link
• no Used link
• no wasGeneratedBy

If a Parameter value is chosen with respect to a Result Entity R, computed on purpose to generate this configuration value, or just reused from a previous excecution,  then the Parameter Instance may have a wasInfluencedBy  relation to this Result Entity R. This Entity R is then described in the system with the usual Entity links wasGeneratedBy and the Activity generating this value may also be described. The WasInfluencedBy relation is part of the relations defined in the vo-dml list of relations (College Park version).

The description of this parameter is stored in the ParameterDescription instance, which is connected via a Parameter --> ParameterDescription link, a Subset of Entity --> EntityDescription link

This allow Parameters to be totally focused on the Configuration part of the Provenance DM , but still be traced to the Entities they may be derived from when necessary.

Identified and dedicated access to the configuration  information allows to trace and interpret the quality of the activities /result Entities more efficiently than sorting between Entity types and Used relations types.