This paper reports on a comparison of the results of two studies which involved the testing and interviewing of students from Year 3 to Year 12 in New South Wales schools. The targeted topic areas were Geometry (2-D figures) and Biology (plant growth). The SOLO Taxonomy was used as the vehicle to categorise the responses. The results in both studies identified cycles of development in the students' answers. The purpose of this article is to explore the differences and similarities between the cycles and provide a window into how students' conceptual understandings develop.