For choosing the type of controlled vocabulary, the most common choices are a thesaurus, a hierarchical taxonomy, or a faceted taxonomy. It is also possible to have some kind of combination or hybrid type of these. I’ve discussed the difference between taxonomies and thesauri in previous blog posts, “Taxonomies vs. Thesauri” and “Taxonomies vs. Thesauri: Practical Implementations.”
So, now I will focus on whether to have the same controlled vocabulary or distinct controlled vocabularies to serve different business needs.
What are different business needs? Taxonomies may be needed to make different kinds of information organized and easily searched or discovered and retrieved by different users, including:
- Internal documentation, including policies and procedures, market and product research, etc.
- Digital assets for content managers to reuse in publishing content
- Product information, such as a product catalog for ecommerce, for customer
- Curated, premium content for subscriber
- Informational content for the public
Taxonomies are versatile, so it is possible and worth considering having a single, master taxonomy serve all business needs, with terms classified for different uses. Terms managed in a taxonomy management system can be tagged with a category assignment as to which use they are for, such as some for an internal use, some for an external, and perhaps many of them for both. You determine the type of category, let’s say “audience”, determine what audience types there are, such as “internal” and “external,” and set that up in the categories option of your taxonomy management software. Then you assign the categories, as appropriate to each term. This method works if the same terms and the same structure are being used in both cases, with one use having more specific terms in some areas. The other use may have less specific terms, or also more specific terms in other areas.
The method of using the same taxonomy for different uses, designating use by categories on terms requires
- that when a concept in the taxonomy has more than one use, that the same preferred term label is used for the concept in both/all cases
- that concepts/terms in the taxonomy have the same relationships to each other
If you want to maintain links between equivalent terms, whether they have the same preferred labels or not, in different business-use versions, it’s not necessary to maintain them in the same taxonomy akin to multilingual versions. Rather, if you created two separate taxonomies, you could still set up inter-taxonomy links between the equivalent terms. This is not necessary, but might be desirable.
Whether to maintain one or more taxonomies also depends on the size of each. If one of the business use cases requires only a small taxonomy, of a couple hundred terms or less, then it is not too much trouble to maintain distinct taxonomies for each.