Extracts from Primary Multimedia Objects and 'Educational Metadata': A Fundamental Dilemma for Developers of Multimedia Archives
Paul Shabajee
D-Lib Magazine June 2002 Volume 8 Number 6
...developers are seemingly forced to make choices about who their target users are and how they will want to use the resources...

...metadata provides the 'hooks' by which objects can be extracted from a database system...

In practical and theoretical terms, it would be impossible for [projects] to tag all of their multimedia assets with all of the possible metadata terms from all possible metadata vocabularies to support all possible educational uses of an asset.

Choosing a manageable number of metadata terms (from the very large number possible) will depend on the context in which the resource will be sought and utilised. This means that even if it was decided to say nothing about how an asset might be used, that is, not to use the metadata elements related to 'possible use', the descriptive metadata terms chosen would necessarily depend on conscious or sub-conscious assumptions about who will use it and how...

You don't want to (and can't) predict what your users will want to use the 'raw' multimedia assets for, but if you don't, your users can't get to the assets.

All that extending the metadata vocabulary can do, in principle, is extend the usefulness of the system to a wider range of users. It does not solve the fundamental problem that it is not possible to know or predict what users will want to access the collection of raw assets to do, or from what perspective.

...it is necessary to have or create some kind of 'semantic hook(s)' in the data to allow users to begin the process of indexing the collection from the new perspective, using the new vocabulary.

...Broadly speaking, an ontology is a formal, explicit specification of a shared conceptual model; it describes the terms used and their relationships in a machine-readable manner...

...the underlying problem is that it is simply impractical, if not impossible, to index all objects under all possible and appropriate indexing terms. Thus it appears that better metadata alone cannot be the solution to the dilemma.