Using subject terms to find desired content contrasts with using a search engine for full text search. Search is based on the occurrence of words, not concepts, so appropriate results can be missed if they use different wording for the same concept, and inappropriate results can be retrieved if a word has multiple meanings. The accuracy of search, without the additional support index terms/subjects, is dependent instead on the sophistication of algorithms. The combinations of algorithms have improved only slightly in the past decade or two. What has made a bigger difference in retrieving good results through search (without subject indexing), is that in many cases the volume of content has grown, and when search results are arranged by relevancy, a larger number of initially displayed search results are satisfactory.