Advanced Search in Retreat by Greg R. Notess
What is your favorite style for a search page? Many librarians like to default to an advanced search page that shows a variety of limits, field searches, boxes for constructing Boolean search statements, and unique features of the search system. Other searchers tend to prefer a simplistic, single search box that does not require much thought before entering a search query. When given a choice, the majority of searchers lean toward a single search box without options. Google reports that only a small minority of searches come from its advanced search page.
Basic search and advanced search are terms that have, in general, come to represent certain types of search interfaces. To generalize, basic search is typically a single box, while advanced search is a longer page with a variety of boxes, limits, and other search options. While advanced search form users are in the minority, there has been a long tradition of having a small link to advanced search capabilities somewhere near that single search box on a basic search page—at least until recently.
Source: Online Magazine.