A Slow Algorithm Improves Users’ Assessments of the Algorithm’s Accuracy

Park, Joon Sung; Barber, Rick; Kirlik, Alex; Karahalios, Karrie
Proceedings of the ACM on Human-Computer Interaction

With computational algorithms making an increasing number of deeply consequential, and often problematic judgments on our behalf, there is a growing interest in slowing down technology to encourage users to reflect on judgments made by algorithms. Prior work in slow technology has established slowness as an agent of reflection and serendipity; however, it has been unclear whether this waiting time actually helps users gain useful insight or any other benefits as they make judgments using an algorithm. To this end, we conducted a series of online and in-person between-subject user studies in which we isolate the impact of an algorithm's speed on how users incorporate the algorithm's advice when making judgments in the context of simple visual recognition tasks. We find that our participants followed good quality algorithms more and bad quality algorithms somewhat less if the response time of the algorithm is slower. Furthermore, qualitative analysis of the in-person study interviews reveals that the waiting was not time wasted, but was often used to reflect on the task and the estimation process of themselves and the algorithm, and to compare and reevaluate the two processes. Based on these findings, we outline design implications of future algorithmic systems.