This paper discusses an instructional approach designed to help preservice teachers understand how assessments can be influenced by personal biases. In order to achieve this objective, we developed an analogy-based activity called "The Dog Show Analogy." After participating in the activity, we have observed that the participating preservice teachers are more aware of how their personal biases can impact the way they assess students. We explain the activity in detail in order to stimulate further discussions and reflections among teacher educators. In addition, we discuss how the development of the activity and the analysis of the data changed our perspectives on student assessment and stimulated future research. (Contains 1 figure and 2 tables.)