Factors Impacting Elementary School Students’ Engineering Design and Optimization Decisions

This mixed methods study explored possible factors that could impact elementary school students’ engineering design and optimization decisions. Data were collected from six teachers and 117 students in six fourth grade classrooms that implemented the Engineering is Elementary geotechnical engineering unit, A Stick in the Mud: Evaluating a Landscape. Students were to recommend to villagers their site decision of where to build a TarPul bridge based on four properties: soil type, villager preference, amount of compaction needed, and location less prone to erosion. Data sources included a pre-and post-assessment question, students’ documentation of property choices for their first and optimized design decisions, student lists of constraints and criteria to solve the problem, and teacher interview responses. Statistically significant differences in student design decisions were identified, and these findings were contextualized with qualitative analyses. The results suggest that design decisions were influenced by the following factors: (a) the students’ understanding of the geotechnical disciplinary concepts needed to solve the engineering problem, (b) each teacher’s chosen supplemental instruction based on content of which they identified students were unfamiliar, and (c) the students’ emotional connections to an idea or belief. From comparing students’ design decisions and teacher reports of their supplementary instruction for a selected property, the findings revealed that students in each respective class privileged the emphasized property in their design decisions. Of less influence were students’ early and sometimes incomplete identification of constraints and criteria. Examination of students’ optimization decisions indicated that most students considered trade-offs as they weighed the advantages and disadvantages of each property, whether or not they initially had prioritized a particular property. The results provide insight into the benefits and implications of teachers’ instructional decisions when supporting elementary school students’ engineering design problem-solving as well as factors students consider when making design decisions.