This study is a qualitative analysis of the work of preservice special education teachers on an activity during which they had to design a game that represented the concept of working memory. The study draws from the framework of model-eliciting activities that require students to develop structural representations of concepts that can be used to demonstrate their understanding of a topic. In this study, the students' models were useful tools for discussing and demonstrating the concept of working memory, which provided the instructor with valuable opportunities for formative and summative assessment. The researchers discuss the connection between the data in this study and the work on model-eliciting activities in other fields and how this research can inform the teaching of preservice special education teachers.