National reform documents and shifts in educational standards have continued to highlight the importance of engineering and engineering practices within science literacy. High-quality engineering opportunities must be present in formal education due to their association with problem-solving and critical thinking. Given this directive to reach students, education reform must also focus on in-service and pre-service teachers who will provide these opportunities to students. One way to investigate elementary teachers' understanding of engineering is to collect conceptual diagrams. We have leveraged construct-centered design to develop and empirically ground a tool focused on engineering education: Draw-An-Engineering-Teacher-Test (DAETT). This instrument provides pre-service teachers and elementary educators the opportunity to capture pre/in-service teachers' mental images and reflect on what they believe engineering would and could look like in the classrooms. This project documents the piloting, development, and validation (K = 0.87; 95% CI = 0.742 to 0.989; p < 0.005) of the DAETT to record pre-service teachers' conceptualizations around engineering education.