This poster reports the preliminary results of a comparative transaction log analysis study of user searching at collection and item levels in a large-scale cultural heritage digital library that provides a unique option for collection-level search. Substantial changes in user searching have been observed over time, including an important trend of the growing use of collection-level search feature. Results also demonstrate differences in the search query lengths, frequencies, and distribution of search categories between the collection-level and item-level searching. The higher occurrence of place and concept categories in collection-level user searches than in item-level searches has been consistent over time. The analysis also revealed the prevalence of subject searching (including concept, object, event, place, class of persons, and ethnic group search categories) both at the collection level and at the item level.

This study provides empirical data to support digital library developers' decision making regarding information organization in large-scale aggregations of digital collections.