Usage patterns of a web-based library catalog

This article reports on a model and patterns of use of a library catalog that can be accessed through the Internet. Three categories of users are identified: individuals who perform a search of the catalog, tourists who look only at opening pages of the library catalog's site, and Web spiders that come to the site to obtain pages for indexing the Web. A number of types of use activities are also identified, and can be grouped with the presearch phase (which takes place before any searching begins): the search phase, the display phase tin which users display the results of their search), and phases in which users make errors, ask the system for help or assistance, and take other actions. An empirical investigation of patterns of use of a university Web-based library catalog was conducted for 479 days. During that period, the characteristics of about 2.5 million sessions were recorded and analyzed, and usage trends were identified. Of the total, 62% of the sessions were for users who performed a search, 27% were from spiders, and 11% were for tourists. During the study period, the average search session lasted about 5 minutes when the study began and had increased to about 10 minutes 16 months later. An average search consisted of about 1.5 presearch actions lasting about 25 seconds, about 5.3 display actions, and 2.5 searches per session. The latter two categories are in the range of 35-37 seconds per session each. There were major differences in usage (number of searches, search time, number of display actions, and display time), depending upon the database accessed.