From the AHDS blog:

The AHDS has done some investigation of the user statistics of the Stormont Papers resource. Two main points are uncovered

1. User searches show the 'long tail' effect. The bulk of searches are not on the most popular terms (which account for 21% of searches) , but on terms, phrases and words that are used very rarely (which account for 54% of searches)

2. Of the ten most popular search terms, all are available as pre-arranged links on the home page. A quick click on a link, rather than typing something into a keyboard, provides a more user-friendly way for a user to get to know what is within a resource.

Source: Users do not want what you expect, AHDS.