Repeatability underpins a basic assumption in science which students must learn in order to evaluate others' research findings as well as to communicate the results of their own research. By attempting to repeat the methods of published studies, students learn the importance of clear written communication, while at the same time developing research skills. I describe three examples of published field studies that can be used as the basis for course exercises on the repeatability of methodology, as well as field sampling techniques, all grounded in the overall topic of environmental change. Two of the exercises returned students to the exact location of the past research that they had previously read from the primary literature, making it possible to clarify the difference between reproducibility and repeatability in field-based research. When student-collected data differed from published results, students explored, through both post-project discussions and written work, factors that could explain this variation, including methodology, ecological succession, and climate change. Assessments and student comments on course evaluations showed that these exercises have a positive impact on students' communication skills and engagement with the scientific process.