This study examines sensemaking in student test case design, showing a reliance on conceptual knowledge learned during programming courses over exploratory testing strategies. Of the three identified approaches taken by students, the ``developer approach'' is used most often, suggesting a gap in software engineering education. We hypothesise that software testing should be taught in computer science programs using a design paradigm based on empiricism instead of rationalism. Based on these results, and our hypothesis, we will further analyse the sensemaking processes of both students and experts, and create an instructional design to improve software testing education in computer science programs.