Drag-and-drop query refinement and query history visualization for mobile exploratory search

Abstract

Search plays a crucial role in digital public libraries due to the vast amount of information available to users. These users often require support because their search tasks are inherently complex. Complex search tasks, characterized as ill-defined, open-ended, or multi-faceted, occur when the information need cannot be satisfied by simply finding a single optimal resource; searchers are required to revise, refine, and reformulate their queries multiple times. One challenge that users face is how to refine their queries. This challenge is compounded when using a mobile device, where typing is time-consuming and error-prone. Conducting searches in a mobile context adds yet another challenge: the possibility of being interrupted and losing track of the ongoing task. To address these challenges, a novel digital public library search interface, optimized for mobile device use, was designed with two key features: drag-and-drop query refinement and query history visualization. To assess the value of this interface compared to a baseline interface, a controlled laboratory study was conducted with 32 participants. The data analysis results highlight the value of the novel interface in terms of usability measures for search activities (including query refinement), search performance, usability measures during the resumption of search tasks, and task resumption performance. Additionally, the results indicate a significant boost in certainty about the search topic after using the novel interface, unlike the baseline, where no change in certainty was observed. Overall, this user study provides evidence that drag-and-drop interactions can effectively support mobile users in refining their queries. Additionally, it demonstrates the beneficial use of visualization in displaying query history when users need to resume their search tasks.