Measures for IR-Effectiveness

Different aspects determine the effectiveness of Information Retrieval. The measures that are used most often are precision and recall. However, in literature different definitions of these measures are sometimes found. So far no experiments have been conducted to determine the usefulness of all these measures for hypertext-based Information Retrieval. Precision and recall have been used most often. Some applications (in law and in patent searches for instance) require 100% recall, i.e. no relevant document may be left out, while other applications like searching on the Web benefit from high precision. Users do not want to find irrelvant documents, while there are so many relevant documents that it does not matter that not all of them are found, because the user has no time to read them all anyway.