Facets are the lenses we use to classify.
A facet is a discrete piece of knowledge you can use to classify something. The more facets something has, the more ways it can be organized.
Using the record store as an example, the following facets are available for each record:
- Record Name
- Artist Name
- Record Label
- Release Date
If a particular facet is interesting but the data to support it doesn't exist or is hard to gather, it might not be the best plan to use that facet.
For example, finding out which instrument models were used on each album may be interesting, but it is also likely to be quite time-consuming to collect.