Document Type



This paper examines the changes of information searchers’ topic knowledge levels in the process of completing information tasks. Multi-session tasks were used in the study, which enables the convenience of eliciting users’ topic knowledge during their process of completing the whole tasks. The study was a 3-session laboratory experiment with 24 participants, each time working on one subtask in an assigned 3-session general task. The general task was either parallel or dependently structured. Questionnaires were administered before and after each session to elicit users’ perceptions of their knowledge levels, task attributes, and other task features, for both the overall task and the sub-tasks. Our results support the assumption that users’ knowledge generally increases after each search session, but there were exceptions in which a “ceiling” effect was shown. We also found that knowledge was correlated with users’ perceptions of task attributes and accomplishment. In addition, task type was found to affect several aspects of knowledge levels and knowledge change. These findings further our understanding of users’ knowledge in information tasks and are thus helpful for information retrieval research and system design.


Library and Information Science


NOTICE IN COMPLIANCE WITH PUBLISHER POLICY: This is the authors’ final accepted manuscript version (‘post-print’) of a work that was accepted for publication in Information Processing and Management. Changes resulting from the publishing process may not be reflected in this document. This version has been formatted for archiving; a definitive version was subsequently published in Information Processing and Management 49(5): 1058-1074. DOI:

ipam.2013.v49.i5.unformatted.docx (147 kB)
Unformatted authors final accepted manuscript