Why On-Site Searching Stinks
http://www.uie.com/articles/search_stinks/

User Interface Engineering
1997

Abstract:

In our most recent web-site studies, we watched users look for information within web sites. Our goal was to gather data about what makes a good link, but we did not tell users whether or not they should use the site’s search facilities. Users went to these search engines in almost half the tasks. Maybe they shouldn’t have.