With the new cirrus based implementation of wbsearchentities, we gain the ability to tweak a great number of parameters that influence search results. In order to optimize these, we need metrics for measuring search result quality.

Note that there are two distinct use cases:

1. the "quick search" box, usually shown on the top right of every page.
2. the entity selector widget shown when editing a statement that references an item.

Both use cases currently use the same widget, and the same API module. This may however change in the future.