Ordinary Search Engine Users

Web search engines have become the dominant tools for finding information on the Internet. Due to their popularity, users apply them to a wide range of search needs, from simple look-ups to rather complex information tasks. This paper presents the results of a study that investigated the characteristics of these complex information needs in the context of Web search engines. The aim of the study was to find out more about (1) what makes complex search tasks distinct from simple tasks and whether it is possible to find simple measures for describing their complexity, (2) whether search success for a task can be predicted by means of unique measures, and (3) whether successful searchers show a different behaviour than unsuccessful searchers. The study includes 56 ordinary Web users who carried out a set of 12 search tasks using current commercial search engines. Their behaviour was logged with the Search-Logger tool. The results confirm that complex tasks show significantly different characteristics than simple tasks. Successful search behaviour can be distinguished from unsuccessful search behaviour. The implications of these findings for search engine vendors are discussed.