The Impact of Technical Domain Expertise on Search Behavior and Task Outcome

Domain expertise is regarded as one of the key factors impacting search success: experts are known to write more effective queries, to select the right results on the result page, and to find answers satisfying their information needs. Search transaction logs play the crucial role in the result ranking. Yet despite the variety in expertise levels of users, all prior interactions are treated alike, suggesting that weighting in expertise can improve the ranking for informational tasks. The main aim of this paper is to investigate the impact of high levels of technical domain expertise on both search behavior and task outcome. We conduct an online user study with searchers proficient in programming languages. We focus on Java and Javascript, yet we believe that our study and results are applicable for other expertise-sensitive search tasks. The main findings are three-fold: First, we constructed expertise tests that effectively measure technical domain expertise and correlate well with the self-reported expertise. Second, we showed that there is a clear position bias, but technical domain experts were less affected by position bias. Third, we found that general expertise helped finding the correct answers, but the domain experts were more successful as they managed to detect better answers. Our work is using explicit tests to determine user expertise levels, which is an important step toward fully automatic detection of expertise levels based on interaction behavior. A deeper understanding of the impact of expertise on search behavior and task outcome can enable more effective use of expert behavior in search logs - essentially make everyone search as an expert.