Cost and benefit analysis of mediated enterprise search

The utility of an enterprise search system is determined by three key players: the information retrieval (IR) system (the search engine), the enterprise users, and the service provider who delivers the tailored IR service to its designated enterprise users. Currently, evaluations of enterprise search have been focused largely on the IR system effectiveness and efficiency, only a relatively small amount of effort on the user s involvement, and hardly any effort on the service provider s role. This paper will investigate the role of the service provider. We propose a method that evaluates the cost and benefit for a service provider of using a mediated search engine - in particular, where domain experts intervene on the ranking of the search results from a search engine. We test our cost and benefit evaluation method in a case study and conduct user experiments to demonstrate it. Our study shows that: 1) by making use of domain experts relevance assessments in search result ranking, the precision and the discount cumulated gain of ranked lists have been improved significantly (144 and 40 respectively); 2) the service provider gains substantial return on investment and higher search success rate by investing in domain experts relevance assessments; and 3) the cost and benefit evaluation also indicates the type of queries to be selected from a query log for evaluating an enterprise search engine.