Unobtrusive interaction: a systematic literature review and expert survey

Unobtrusiveness has been highlighted as an important design principle in Human-Computer Interaction (HCI). However, the understanding of unobtrusiveness in the literature varies. Researchers often claim unobtrusiveness for their interaction method based on their understanding of what unobtrusiveness means. This lack of a shared definition hinders effective communication in research and impedes comparability between approaches. In this article, we approach the question "What is unobtrusive interaction?" with a systematic and extensive literature review of 335 papers and an online survey with experts. We found that not a single definition of unobtrusiveness is universally agreed upon. Instead, we identify five working definitions from the literature and experts' responses. We summarize the properties of unobtrusive interaction into a design framework with five dimensions and classify the reviewed papers with regard to these dimensions. The article aims to provide researchers with a more unified context to compare their work and identify opportunities for future research.