Formative assessment is one of the strongest instructional signals students receive about what matters in a course. As the course instructor, I intentionally designed and implemented a mixed-format assessment strategy by rotating closed-book, open-book, and crib-sheet exams shape how students prepare and apply precision agriculture concepts. This teaching practice was implemented in an undergraduate Precision Agriculture course  with 51 students (2 academic year). Closed-book exams targeted conceptual integration, crib-sheet emphasized prioritization and synthesis, and open-book exams were structured to reflect agronomic decision contexts. The results (using Likert scale 1 to 5, low to high understanding) show exam format changes learning behavior. Understanding was highest for crib-sheet exams (mean = 3.84) and closed-book exams (mean = 3.71), and lowest for open-book exams (mean = 3.29). Open-book exams were less challenging than closed-book by 0.46 rating units and had the lowest challenge (mean = 2.78 versus 3.27 for closed-book). Students invested the most effort when conceptual mastery was required: the median preparation time for closed-book exams was 4 hours, compared with less than 2 hours for open-book. Crib-sheet exams showed the largest spread in preparation time, indicating wide variation in how students organized and synthesized material. Stress (using Likert scale 1 to 5, not stressful to extremely stressful) did not differ across formats (means: 3.25 closed-book, 2.76 open-book, 3.22 crib-sheet). Higher understanding associated with closed-book and crib-sheet exams was not explained by increased stress, but by cognitive engagement. Students were least motivated to study for open-book exams, even though they reported higher in-exam confidence. A mixed-format exam was preferred by 55%  of students  and among single-format choices, crib-sheet exams were most preferred. A mixed-format strategy provides a transferable way to intentionally train applied learning skills applied courses like precision agriculture rather than rewarding short-term recall alone.