Understanding Search Engines : Requirements for Explaining Search Results

There are three different groups that use Commercial Web Search Engines: the Developers, the Evaluators and the EndUsers. Each group has different information needs and applies different criteria when examining the retrieved documents. Most Search Engines attempt to measure retrieval performance providing figures of recall and precision, indicative of the quantity of the obtained information but saying too little about the quality of this information. In this paper we present a survey of the requirements that each user group has and we propose a generic framework, independent of the details of the underlying Search Engine. Our aim is to provide users with explanation utilities regarding qualitative information of the returned documents. This study’s motivation emerged from real life experience acquired during the development of a Web Search Engine for Greek and our purpose is to explain the most usual difficulties in user understanding of Search Engines’ operation.