Within primary and secondary school technology education, engineering has been proposed as an avenue to bring about technological literacy. Different initiatives such as curriculum development projects (i.e., Project ProBase and Project Lead The Way) and National Science Foundation funded projects such as the National Center for Engineering and Technology Education (NCETE) have been developed to infuse engineering into primary and secondary education. Through the efforts of NCETE, three core engineering concepts within the realm of engineering design have emerged as crucial areas of need within secondary level technology education. These concepts are constraints, optimization, and predictive analysis (COPA). COPA appears to be at the core of the conceptual knowledge needed for students to understand and be able to do engineering design. One of NCETE's five technology teacher professional development institutions (Illinois State University) has focused exclusively on the delivery of these COPA concepts. These concepts have emerged as distinctly important. At Illinois State University, two cohorts of practicing and pre-service technology teachers have engaged in professional development workshops to become better prepared to deliver engineering concepts to their students. Through discussions about the nature of engineering and engineering design, how it differs from technology education processes, and the necessary conceptual and procedural knowledge, COPA was identified as necessary for the delivery of engineering design. Empirical knowledge is needed to better understand how to increase student learning of COPA. This study seeks to provide that knowledge using a NCETE cohort of practicing and pre-service technology teachers who designed and developed a unit of instruction to deliver these three core engineering concepts to secondary level technology education students. Using a mixed method quasi-experimental, pre-test post-test no control group design, this study explores the extent to which students understood and were able to demonstrate an understanding of COPA. It is believed that through this strong conceptual base, a better understanding of engineering and engineering design can be achieved. (Contains 3 tables.)