 This video is part 2 of our series on User Engagement and User Engagement Research. In our last video, we defined user engagement and described user engagement research methods. This video will highlight user engagement research that explores individual differences and domain knowledge. First, individual differences. Last time, we talked about individual characteristics, which can be a person's familiarity with a certain platform. Individual differences, however, are rooted in psychology and include the demographic, cognitive, psychomotor such as hand-eye coordination and interpersonal characteristics that differentiate and unify people. Understanding which individual differences affect specific outcomes such as user satisfaction, user groups such as older adults, and contexts such as a person's workplace can help inform the design of information systems and services for specific populations. In this study, O'Brien, Dickinson, and Askin reviewed scholarship on individual differences. They retrieved over 2100 articles and applied scoping methodology to narrow them down. Ultimately, they analyzed 223 articles in more depth. From these papers, the authors analyzed the types of individual differences that were studied, publication volume over time, measures and measuring instruments, samples, and study outcomes. The researchers found that while there's robust scholarship on individual differences, it's unclear if general conclusions can be made from this body of research. This is because most subjects for a university age, the measuring instruments may not be reliable, and the definition of specific individual differences may vary. Next, we'll explore domain knowledge. Domain knowledge is having expertise on a specific topic or activity. This paper by O'Brien, Kampin, Cole, and Brennan reports on preliminary findings that explored individual differences in domain expertise and defined searching as learning. The authors analyzed how, when searching a digital library, individuals who say they're a subject area expert or domain experts and individuals who don't think they're an expert in that same subject area or non-experts might reach different conclusions or learning outcomes when performing the same search. The researchers defined the concept searching as learning, which is driven by finding an answer as well as the searcher's experience in discovering, analyzing, and evaluating the information from a wide-ranging search. The researchers are trying to understand how individual differences affect learning processes and outcomes and can support the design of innovative search tools. Furthermore, the researchers thought that domain expertise would influence successful searches. During the study, domain experts and non-experts searched a digital library. Their search tasks involved three different types of information searches. Participants also wrote summaries and filled out questionnaires before and after completing each search task. The search tasks that the participants performed were designed to provoke different cognitive processes and behaviors. The tasks were factual, such as researching tools that were used to find gold, exploratory, such as exploring gold mining techniques, and interpretives such as investigating how the gold rush impacted the formation of British Columbia. While domain experts wrote better summaries before doing their search tasks, non-experts wrote summaries that were as good as the domain experts after they did their search. Therefore, there were no significant differences in the learning outcomes between the two groups. Our next video will continue exploring specific aspects of user engagement research, including task determinability and interest, task complexity, and search behavior. We hope you join us and thanks for watching.