Search Timelines: Contextualized search history in support of exploratory search

Abstract

The timespan over which exploratory searching can occur, as well as the scope and volume of the search activities undertaken, can make it difficult for searchers to remember key details about their complex search tasks. These difficulties are present both during a single search session and when resuming a search task that spans multiple sessions. Existing public digital library search interfaces do not provide adequate support to allow patrons to pursue a complex search task for a prolonged period across multiple sessions. In this thesis, I present a novel search interface designed to support cross-session exploratory search in a public digital library context through the introduction of Search Timelines. The interface provides context for past and current search activities via a dynamically updating timeline of the search (queries and saved documents). This timeline is presented alongside the search results in a typical search engine results page design. A more detailed timeline is provided in a workspace, where searchers can review the history of their search activities and their saved resources. In order to assess the value of Search Timelines, a controlled laboratory study was conducted to compare it with a baseline interface modelled after the Regina Public Library search interface. The results of this study show that searchers were more engaged while working with Search Timelines both during the initial search session and when resuming the search after a gap of 7-8 days. The results also show the value of the novel interface in terms of usability measures, perceived knowledge gain, and search performance for both initial and resumed sessions. Overall, the results illustrate that Search Timelines can effectively support public digital library searchers while performing exploratory search that span multiple sessions.