Grounded theory methodology allows researchers to generate theories that answer research questions that existing theories do not adequately explain. This methodology involves the use of the constant comparative method in an iterative cycle of data collection and analysis. To understand the data and make decisions that drive the cycle forward, the researcher may use diagrams and memos. This case describes the step-by-step use of diagrams in one grounded theory study that addresses the research question: 'How do administrators in high-poverty middle schools decide how to respond to students' challenging behaviors?' Through the use of diagrams, the research team made decisions about how to develop codes, how to relate codes to each other to form themes, and ultimately how to formulate a theory that would answer the research question. This case study includes examples of the diagrams used in this case along with a detailed explanation of how each type of diagram played an important role in data collection and analysis. [This content is provided in the format of an e-book.]