A recent taxonomy project I completed involved creating a new taxonomy for a financial services client who was migrating its internal content from shared drive folders to a SharePoint-based intranet, which also included automated indexing and a search engine (FAST). The new taxonomy will help support the search functionality, and taxonomy terms will also display in the left-hand margin (called the Refinement Panel), so that users can refine/narrower their initial search results by selecting terms from several attributes/filters/facets. The client had already made an attempt at the start of a taxonomy by the time I had become involved. Not surprisingly, the client-created taxonomy followed the structure of the existing folder names quite closely. After all, the folder structure was their only reference point. It became apparent that a taxonomy for folders and a taxonomy for facets, even for the same content, should be designed quite differently.
A hierarchy of nested folders has the following characteristics:
- It is designed to gather and group similar documents together.
- It is usually designed and created by a person who is uploading/storing documents with the frame of mind of “where can I put these so that I might find them later.”
- A document can go into only one folder and thus under only one category.
- A folder can be located within only one parent folder.
- The hierarchy of nested folders thus may become quite deep, such as six of seven levels.
- Folder names at deeper levels can become long and complex to describe a combination of criteria (a taxonomy design characteristic called pre-coordination).
A faceted taxonomy for search refinement has the following characteristics:
- It is designed to refine and narrower a search by specific criteria.
- It is designed to help all members of an enterprise find documents, including documents uploaded by different people in different departments.
- A document can be assigned multiple taxonomy terms, even terms from within the same facet/broad category.
- A taxonomy term may display “under” more than one parent taxonomy term, as long as it is a logical hierarchy. (This feature is called “polyhierarchy.”)
- The displayed hierarchy of terms is not so deep, usually only three levels.
- Taxonomy term names stay simple, since they are intended to be used in combination (a taxonomy design characteristic known as post-coordination).
With this many differences between hierarchical folders and refinement facets, it’s inevitable that the taxonomy for each will differ, even if the content/documents and the users remain the same. Actually, a nested folder structure may or may not even constitute a “taxonomy.” It depends on whether the folder system was designed with a consistent structure and folder names or whether it just grew ad hoc.
A year and a half ago I was involved with a similar taxonomy project for the wind energy company First Wind. In addition to designing a faceted taxonomy for the Refinement Panel to support search in SharePoint, I was also tasked with improving the nested folder structure and folder names already in use in SharePoint, and which was not going to go away. I remember being asked then, if I could just create a single taxonomy for both purposes. The answer was no, not entirely. There would be overlap, but there would also be differences. To the stakeholders, that seemed like a lot of additional work, but to me, the taxonomist, that’s simply the nature of my work, and I enjoy the diversity of building different kinds of taxonomies. In the end, more work put in the by the taxonomist means less work needed by the users.