Interactive Search Result Clustering: A Study of User Behavior and Retrieval Effectiveness

Scatter/Gather is a document browsing and information retrieval method based on document clustering. It is designed to facilitate user articulation of information needs through iterative clustering and interactive browsing. This paper reports on a study that investigated the effectiveness of Scatter/Gather browsing for information retrieval. We conducted a within-subject user study of 24 college students to investigate the utility of a Scatter/Gather system, to examine its strengths and weaknesses, and to receive feedback from users on the system. Results show that the clustering-based Scatter/Gather method was more difficult to use than the classic information retrieval systems in terms of user perception. However, clustering helped the subjects accomplish the tasks more efficiently. Scatter/Gather clustering was particularly useful in helping users finish tasks that they were less familiar with and allowed them to search with fewer words. Scatter/Gather tended to be more useful when it was more difficult for the user to do query specification for an information need. Topic familiarity and specificity had significant influences on user perceived retrieval effectiveness. The influences appeared to be greater with the Scatter/Gather system compared to a classic search system. Topic familiarity also had significant influences on query formulation.