The usually interesting Jackob Nielsen's current alertbox is about mental models of search:
Search is such a prominent part of the Web user experience that users have developed a firm mental model for how it's supposed to work. Users expect search to have three components:He goes on to suggest that departing from this mental model causes confusion. He also suggests that 'parametric searching', where one searches for something based on several attributes of the thing sought, is best not labelled 'search', because this does not fit the mental model.
[Mental Models For Search Are Getting Firmer (Jakob Nielsen's Alertbox)]
- A box where they can type words
- A button labeled "search" that they click to run the search
- A list of top results that's linear, prioritized, and appears on a new page -- the search engine results page (SERP)