A longitudinal study of the effects of OPAC screen changes on searching behavior and searcher success

A longitudinal study of four sets of OPAC transaction logs was conducted ov er a four-year period. Analysis of the initial set of transaction logs reve aled problems that users experienced while searching the OPAC. Over time, a series of OPAC screen changes were implemented in an attempt to help searc hers improve their searching behavior. After each series of changes, a set of transaction logs was analyzed to assess the impact of the changes and to study whether earlier improvements in searching behavior persisted over ti me. Although the screen changes initially had a positive impact on searchin g behavior, in some cases the initial improvements in searching success wer e not sustained over time.