This study illustrated a pathway of growth that a preservice teacher might traverse when learning to use and develop equitable assessments (EA). The study is rare in that it looks at the development of preservice teachers' understanding and ability to design EA. I examined the understanding and implementation of EA of 23 secondary preservice teachers within two classes. The methods classes focused on the academic content area of science. Participants' journals, teaching philosophies, and inquiry-based science units served as data sources. Participants progressed from a simple view of EA as "fairness" to a more sophisticated view of EA, including: ways to increase fairness, the importance of challenging students, and using assessments for learning. Results also showed changes in preservice teachers' views of learners and the purpose of assessment. While understanding developed robustly, teachers' assessment plans in their units were not as strong. Teacher education programs need to place more emphasis on developing critical understanding of EA practices to meet the needs of diverse learners.