A ratio that measures the success of a search. Precision is defined mathematically as the number of relevant items returned by a search divided by the total number of items returned by the search. Thus, a search that returned only relevant items would have a precision of 1.0.

      Precision usually has an inverse relationship to recall. That is, increasing the precision of a search usually decreases the recall. Precision can be increased by increasing the specificity of vocabulary terms. For more information, see: