Work in progress - relationship of demonstration construction quality on pedagogic effectiveness

Scientific studies have established the importance of engineering demonstrations, yet comparatively little is known about what makes some demonstrations more effective than others. In this study we investigate the pedagogic effect of demonstration construction quality. This study considers two build qualities: ¿raw¿ and ¿polished¿. Raw demonstrations use prototype-quality construction techniques such as exposed solderless breadboards, and polished demonstrations use production-quality construction techniques designed to emulate typical consumer electronics. The impact of the demonstrations on student interest were assessed by constructing paired sets of demonstrations of raw and polished quality. These were used in lectures to 119 students and student interest and comprehension were assessed by post-lecture surveys. Initial data using only a single demonstration in both raw and polished versions show students in both technical and nontechnical majors score higher in objective testing and report higher interest in the material using raw construction techniques (two-tailed p=0.051 and <0.01 respectively). Further data using other demonstrations will be obtained in 2009 to determine if these findings can be generalized.