Impacts of Time Constraints and System Delays on User Experience.

During information search, people often experience time pressure. This might be a result of a deadline, the system's performance or some other event. In this paper, we report results of a study with forty-five participants which investigated how time constraints and system delays impacted the user experience during information search. We randomly assigned half of our study participants to a treatment condition where they were only allowed five minutes per search task (the other half were given no time limits). For half of participants' search tasks, five second delays were introduced after queries were submitted and SERP results were clicked. We used multilevel modeling to evaluate a number of hypotheses about the effects of time constraint, system delays and user experience. We found those in the time constraint condition reported significantly greater time pressure, experienced higher task difficulty, less satisfaction with their performance, increased importance of working fast and engaged in more metacognitive monitoring. We found when experiencing system delays participants reported slower system speeds when encountering delays on the second task. This work opens a new line of inquiry into how time pressure impacts the search experience and how tools and interfaces might be designed to support people who are searching under time pressure. It also presents an example of how multilevel modeling can be used to better understand and model the complex interactions that occur during interactive information retrieval.