摘要：A longitudinal study of four sets of OPAC transaction logs was conducted over a four-year period. Analysis of the initial set of transaction logs revealed problems that users experienced while searching the OPAC. Over time, a series of OPAC screen changes were implemented in an attempt to help searchers 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 time. Although the screen changes initially had a positive impact on searching behavior, in some cases the initial improvements in searching success were not sustained over time.
