The main objective of the study was to investigate the potential mediating effect of relevance in the relationship between attention and confidence in Keller's ARCS model during screencasts in distance education. The paper responds to calls for further research into the ARCS model in different delivery systems, cultural settings, and learner populations, and in terms of the relationship between the motivational components. The study employed design-based research to address practical problems in distance education and used the IMMS survey to collect data. Exploratory factor analysis revealed two factors, attention with interest and basic attention for attention, and two factors, ease of use and self-confidence for confidence. This paper contributes to advance knowledge of design principles, which instructional designers could use when designing learning materials in order to motivate online students.