Faceted Taxonomies

Taxonomy design for digital content management isn’t exactly like traditional taxonomy design. Computers are more flexible than library shelves. Digital content can be in two (or more) places at once.

Further, the ability to find content based on taxonomy facets, means that deeply nested taxonomies are far less often required.

Consider the following hierarchical structure:

This structure is understandable, once it’s been explained. “We organize content by year, then department, then type, then…”

While this structure might be convenient for some users, other users would see it as a hindrance. For example, someone in Marketing might resent having to always navigate through year categories in order to see the Marketing content. Someone else might have a need for advertising materials from some year unknown.

What makes hierarchical organization like this even worse is that with each new year, the entire substructure needs to be created anew.

By contrast, faceted organization enables you to remove the hierarchical requirements and achieve even more flexible (and obvious) results to users. By clicking relevant checkboxes, users narrow in on the results they need, often without any knowledge of the greater taxonomy. If a facet isn’t relevant for a given search, it can be ignored. (For example, maybe the year isn’t important.)

Below is the taxonomy above (with additional options) presented in a faceted model. Most invisibly relevant about this model is that it requires virtually no training. Faceted taxonomies invite users to experiment, whereas clicking in and out through hierarchical taxonomies quickly becomes tiresome and frustrating. (It can also be difficult to remember which branches of the tree you’ve already visited.)

When using a faceted taxonomy approach, only a single new tag will be required for each new year, new department or new content type.

What does need to be considered is the “and/or” aspect of each facet. For example, if 2014 and 2015 were both selected in the example above, it means either “find assets created in either 2014 or 2015” or “find assets created in both 2014 and 2015.”

Some content systems don’t offer both options, meaning their facets are always either “and” or “or,” which can confuse users. For example, someone expecting to see assets from either year (or) might see nothing when selecting both options because no asset was developed in both years (and).

This, of course, is a user experience issue. It’s perfectly possible for a system to indicate which Boolean function is being considered within a faceted group. The challenge might be finding a system whose designers understood the value in doing so.

When designing taxonomies for physical objects and spaces, faceting is not an option. But when designing for CMS or digital asset management systems, it’s important to think about all the advantages available.