Investigating Middle-School Students' Conceptions of Trade-offs in Design∗

The recent reform efforts in K-12 education urge for the integration of engineering with other subject matter such as science. Design, a core practice in engineering, is new to many K-12 students, and thus, little is known about their design strategies and conceptions. One design strategy, making trade-offs, is a necessary design practice, and is a key performance dimension in student design. However, research on K-12 students' conceptions of balancing trade-offs is limited. Such research is essential as we attempt to understand how students become informed designers and how we can support their transformation. Understanding how students prioritize design strategies after taking part in a design activity allows an opportunity to see how students' conceptions of design activities change. In particular, this multi-method work addresses students' use and prioritization of the term ''balancing trade-offs'' in design through the following research questions: (1) Do students report changes in their perceived importance of ''balancing trade-offs'' after engaging in a design project, and (2) How students' conceptions of ''balancing trade-offs'' change after introduction of a design activity. This survey was administered as a pre-and post-Test assessment in three middle schools with over 700 students. We performed McNemar tests to quantitatively understand changing conceptions and qualitatively analyzed open-responses to get a deeper understanding of students' rationale. Results suggest that after a design activity, ''balancing trade-offs'' became a statistically more important concept to students, but that students still did not have a sophisticated understanding of the term without dedicated instruction. # 2018 TEMPUS Publications.