The CONTACT-2 strategy is characterised by CONTinuous, computer-assisted ACTivation of the conceptions of individual learners while they are processing expository texts. A previous study showed that the CONTACT-2 strategy was effective as an instructional strategy aimed at supporting processes of prior-knowledge activation and conceptual change. The present study was designed to explore the (quantitative and qualitative) differences in learning activities between students who were successful and less successful while working with the CONTACT-2 strategy. Subjects were 10 fifth- and sixth-graders (primary education). The way in which the second CONTACT-2 step on "comparing and contrasting their preconceptions with the new information" was being performed by the students appeared to be crucial for the effectiveness of the CONTACT-2 strategy as a whole. Recommendations for future research and educational practice are formulated.