We need a way to merge topics for reasons that are not specified by the TMDM.
For example, I want merge topics that have equivalent occurrences of type ISBN. Library catalogs in different languages may only share the ISBN of an item as a common characteristic. A topic map generated from each of them could have the ISBN as an occurrence on each topic.
I am assuming each topic map relies upon library identifiers for “standard” merging because that is typically how library systems bind the information for a particular item together.
So, how to make merging occur when there are equivalent occurrences of type ISBN?
Solution: As part of the process of creating the topics, add a subject identifier based on the occurrences of type ISBN that results in equivalent subject identifiers when the ISBN numbers are equivalent. That results in topics that share equivalent occurrences of type ISBN merging.
While the illustration is with one occurrence, there is no limit as to the number of properties of a topic that can be considered in the creation of a subject identifier that will result in merging. Such subject identifiers, when resolved, should document the basis for their assignment to a topic.
BTW, assuming a future TMQL that enables such merging, note this technique will work with XTM 1.0 topic map engines.
Caution: This solution does not work for properties that can be determined only after the topic map has been constructed. Such as participation in particular associations or the playing of particular roles.
PS: There is a modification of this technique to deal with participation in associations or the playing of particular roles. More on that in another post.