If you are looking for information on e.g. the history of France (or Italy or many other countries) in Wikipedia and you just search "history france" you don't get, as you'd expect, the article "History of France" as the first result. It's not even within the 10 first results.
It's not always the case, but it seems that secondary words like 'of' (that many users just don't write in their searches) are being given by the Wikimedia's search engine more weight than they should. (Contrast that with Google for example).
The problem is similar in Wikis in other languages, like Spanish or French. On them, unless you write the preposition 'de' you may not get the results you expect. Examples: 'emisora (de) radio', 'historia (de la) música', 'guerra (de) afganistán', etc.
I can imagine thousands of users having problems to find certain articles because of this. Hope it can be fixed.