ENQUIRE was installed in three locations. The system was publicised as a new way of subject searching and left to run for three months, from January to March 1996. Transaction logs were kept of each search session, and users were asked on-line questions about how they perceived the success of their search. The data collected in this way was analysed, and the results are presented later in this chapter.
The purpose of the field trials was to carry out a summative evaluation of the system, focusing on retrieval functionality. The original intention had been to identify a specific user group with possibly pre-defined information needs, and assess the effectiveness of the group members' information-seeking activities --- in particular their recurrent interaction with the system. It proved impossible to have access to such a homogeneous group of test subjects within the chosen operational setting and the timescale of the project. Hence a more open field trial approach was adopted for the large-scale evaluation in order to attract as many users as possible.
As the data collection had to be totally automatic, i.e. without any intervention from the experimenter, a combination of an online-questionnaire and transaction logging was used. Experience in the previous project had shown that a substantial number of users would ignore a post-search questionnaire even when the mailing of their search results was given as an incentive. In the current project, information about target users had been gathered in the two formative evaluations (see Chapter 4), so given that the transaction logs would be extensive, it was decided to restrict the online questions to two about the user's perception of the success of the search.