INFORMATION-RETRIEVAL EVALUATION IN PRACTICE - A CASE-STUDY APPROACH

The evaluation of information retrieval systems is an important yet difficult operation. This paper describes an exploratory evaluation study that takes an interpretive approach to evaluation. The longitudinal study examines evaluation through the information-seeking behaviour of 22 case studies of 'real' users. The eclectic approach to data collection produced behavioral data that is compared with relevance judgments and satisfaction ratings. The study demonstrates considerable variation among the cases, among different evaluation measures within the same case, and among the same measures at different stages within a single case. It is argued that those involved in evaluation should be aware of the difficulties, and base any evaluation on a good understanding of the cases in question.