You can specify Rank as the sort order when searching (it’s the default) which will put the articles which best matched your search on the top, and the complete results in descending relevance to your search. This feature is useful for finding the most important articles on a specific topic.
You can also change the sort order of results by selecting rank at the top of the search results pane after you perform a search. Note that rank order after a search only ranks up to 1000 maximum results that were returned; specifying rank in the search dialog ranks all possibilities before choosing the final 1000 (or less) to return.