The next topic for attention in late November was the detailed behavior of the dynamic faceting. The aim was to design a mechanism that was driven by the nature of the contents as much as possible. Faceting in situations where every topic has only one value in each facet was seen as fairly straightforward; we concentrated on two cases that we found slightly more complicated.
One case is where some topics are marked-up with multiple values for certain facets. What this implies is that a selection of a facet value during faceting may result in a set of selected topics that have also other selectable values for the same facet.
The other challenging case is where there is a hierarchical structure of facet values for certain facets. This case is often found in product data management (PDM) systems and we found it necessary to address it in order to provide a comprehensive production/use environment for technical information.
The sketch treats the two cases above in some depth. The first case shows how the user combines two facet values from the same facet. In the second case, the sketch shows how a hierarchical facet value structure is flattened through inheritance to provide a user experience similar to the first case.
Our general approach is to limit faceting to simple conjunctive selection. We expect this to be easy to learn for users without previous faceting experience, yet powerful enough in combination with text search and sorting to enable users to find the topics they need.
Facet values are selected as on-off toggles instantly shaping the current selection of topics in the topic list.