All search engines lack a feature that would make them hugely more useful: disambiguation. Suppose I search a common name "John Doe". I should next be presented with a disambiguation page allowing me to select whether I meant "John Doe who was President of Calexico 1905-1909", "John Doe who won the World Series with the Greensocks 1975" or "John Doe professor of Spanish Technicalities at Idaho Institute of Science". It shouldn't be my job to disambiguate my query. The search engine knows much more about the total search space than I do!