Students' development of an understanding of covariation was the focus of a research project that investigated the way in which 12 Year 5/6 students engaged with the learning environment afforded by the graphing software, "TinkerPlots." Using data generated from individual interviews, the results demonstrate that upper primary students use their understanding of covariation to draw conclusions about trends in data evidenced in the graphs they created as well as their knowledge of the context. Implications for the Australian Curriculum are considered. [This research is funded by an APA(I) Scholarship associated with an ARC Linkage Project LP0560543 and the industry partner, Department of Education, Tasmania.]