Are prov:wasDerivedFrom and prov:wasGeneratedBy association properties?

[jakebeal]

The specification is currently contradictory about whether prov:wasDerivedFrom and prov:wasGeneratedBy are association or non-association properties.

• Figure 5 for Identified shows that prov:wasDerivedFrom and prov:wasGeneratedBy are non-association properties with URI values.
• The text writeup of the properties on page 14 and 15 indicates that they are association properties with Identified and prov:Activity objects respectively.
• Figure 27 for prov classes shows that prov:wasDerivedFrom is a non-association property, while prov:wasGeneratedBy is an association property.

We need to decide which it actually is and to fix the specification.

I believe that the key question here is whether a prov:wasDerivedFrom can ever point to anything other than an Identified object and if a prov:wasGeneratedBy can ever point to anything other than a prov:Activity.

Based on the usages to date, I believe that the answer may be:

• prov:wasDerivedFrom is a non-association property: it sometimes gets used very broadly, to point to things like vendors and publications.
• prov:wasGeneratedBy is an association property: it has a stricter requirement on machine-interpretability and can only be pointed at prov:Activity

[jakebeal]

Consensus from mailing list discussion:

• prov:wasDerivedFrom is a non-association property
• prov:wasGeneratedBy is an association property