Interest-based text preference moderates the effect of text difficulty on engagement and learning

•Participants studied four instructional texts on research methods.•Examined interaction between interest-based text preference and text difficulty.•Interest-based text preference and text difficulty interact to predict engagement.•Interest-based text preference and text difficulty interact to predict transfer. Theories of motivation propose that moderate difficulty can be beneficial for student engagement and learning. However, research on the effect of difficulty has been inconsistent. The primary goal of the present study was to investigate the possibility that interest-based text preference moderates the effect of difficulty on engagement and learning. To test this hypothesis, participants studied four instructional texts on research methods topics in a 2 × 2 interest-based text preference (preferred vs. non-preferred texts) × text difficulty (easy vs. difficult) within-subjects experiment. The manipulation of interest-based text preference asked participants to rank four text titles based on their perceived interest in reading the text corresponding to each title. Engagement was assessed via self-reported affect (valence and arousal), attention (mind wandering), and reading time during the learning session. Learning and knowledge transfer were measured with knowledge tests after reading all four texts. Consistent with our predictions, interest-based text preference and text difficulty interacted to predict reading time, mind wandering, and knowledge transfer. The nature of the relationship indicated that increased text difficulty can support engagement and transfer, but only when individuals are provided with an opportunity to express their text preferences prior to reading.