Estimating the satisfaction of information users.
Several factors influence the responses of users of information retrieval systems who are asked to evaluate the service provided by a system. To realistically estimate user satisfaction, different aspects of the search outcome should be explored. This paper analyzes the data obtained in a follow-up questionnaire sent to a sample of MEDLINE users who had requested searches at seven information centers within a two-month period. The questionnaire requested the user's appraisal of the value of the search and of the usefulness of the retrieved references. A comparison of different items of the questionnaire revealed some contradictions between an overall appraisal of the service and more specific responses on the outcome of the search. Caution is advised in inferring the satisfaction of information needs from the users' evaluation of an information retrieval system.