A longitudinal study of exploratory and keyword search

Digital libraries are concerned with improving the access to collections to make their service more effective and valuable to users. In this paper, we present the results of a four-week longitudinal study investigating the use of both exploratory and keyword forms of search within an online video archive, where both forms of search were available concurrently in a single user interface. While we expected early use to be more exploratory and subsequent use to be directed, over the whole period there was a balance of exploratory and keyword searches and they were often used together. Further, to support the notion that facets support exploration, there were more than five times as many facet clicks than more complex forms of keyword search (boolean and advanced). From these results, we can conclude that there is real value in investing in exploratory search support, which was shown to be both popular and useful for extended use of the system.