Controlled Vocabularies

by anchorarchivist... ()

There are some fields in the zine record table for which we want to use a controlled vocabulary. The Taxonomy module allows you to create vocabularies, add terms to these vocabularies, and associate a vocabulary with a particular content type, so that then the vocabulary appears as a field in the content type when one is entering a new item. When entering data into a vocabulary field, a user would normally select a term from a list, but when you create a vocabulary you can also set it up as Freetagging, which means that content is categorized by typing terms instead of choosing from a list. You can also set up a vocabulary as a hierarchy, with broader, related, and use for terms, or you can disable this function in an individual vocabulary.

For the Anchor Archive system, we will create vocabularies for main topic, subject, and author. Main topic refers to the topic name on the box in which a zine is filed. There are around thirty main topics at the Anchor Archive currently. This vocabulary will appear as a drop-down menu from which cataloguers will select a single term. Subject refers to the (usually) multiple subjects covered by a zine. This list will be set up as Freetagging, which will allow cataloguers to select a term that is already part of the subject vocabulary or enter a new term. When they enter a new term, it will automatically get added to the subject vocabulary. While we want to have a controlled vocabulary for subjects and to avoid the appearance of different terms for the same subject in the catalogue, we also recognize that it will be impossible to include all potential subjects in the vocabulary. We hope that this method will allow a good balance of flexibility and control. The subject vocabulary will also be available as a separate document that cataloguers can refer to when assigning subject terms. This is necessary because although when creating a vocabulary in Drupal you can enter “use for” terms and other thesaurus terms, these other terms don’t actually get used in the system itself. The separate thesaurus document will allow cataloguers to reference use for terms and other terms when cataloguing. It can also be used by users who are searching the catalogue by subject.

Taxonomy fields display separately from other fields in the zine record. At first we identified this as a problem and we installed the CCK Taxonomy Fields module because it allows you to turn a vocabulary into a CCK field. We turned the main topic vocabulary into a CCK field and this resolved our display problem but it led to other problems since we lost the ability to do things with the field that are specific to a taxonomy. Because we were no longer associating vocabulary terms directly from the Taxonomy module, other modules which depend on Taxonomy no longer worked correctly. For example, the Directory module, which creates a subject-based browsable directory, ceased to function with main topic terms. Eventually we decided to disable to CCK Taxonomy Fields module and not have taxonomy fields as CCK fields anymore. We should be able to resolve the display issue later when we are theming our site.