Designing and implementing chain reactions: A study of seventh-grade students' knowledge of electrical circuits

This paper describes the implementation and results from the study of a novel teaching and learning experience in K-12 Engineering Education. The specific novel teaching and learning experience focused on a Chain Reaction/Circuits thematic unit. The thematic unit was embedded in a National Science Foundation (NSF) sponsored Information Technology Experiences for Students and Teachers (ITEST) project. The project served over 100 students via a highly engaging after-school engineering education program in four middle schools from traditionally under-represented populations. Seventh-grade students were engaged with the idea of designing a chain reaction after watching the "Cog" a 2003, Honda commercial. Notions of chain reactions such as local actions having global impact were discussed. Students were provided with a variety of technology tools beginning with components for creating a simple circuit (switches, electrical cables, an light emitting diode-LED, buzzers, and a battery pack) and household objects (cardboard, coat hangers, aluminum foil, milk/juice cartons, etc). Students investigated different combinations of the electrical components creating varying types of circuits, progressing to constructing their own homemade switches from the household objects. PICO Cricket kits were introduced and students used the PICO software to program and design intelligent reactions to mechanical actions. Continuing with the PICO Cricket Kits students constructed creations (autonomous art installations) that would respond to stimuli from their surroundings (e.g., sound, movement, touch, and light). Individual and class discussions fortified the relationships between inputs/outputs and chain reactions. Ultimately, the entire cohort engaged in the creation and execution of a large-scale chain reaction (Rube Goldberg Machine). Students were placed into groups of two and given one table. Each group (thus, each table) was connected through wood blocks, when touched would fall into the next wood block, acting as both the group's table input and table output. Student learning was assessed^1,2,3 through formal and informal methods. Informal assessments consisted of open-ended questioning, demonstrations, teacher observations, and student constructions. Formal assessments consisted of pre- and post-assessments specific to unit content. Analysis of formal assessments utilized two sample dependent t-tests to determine if significant differences existed across pre- and post-assessments. Analysis showed a statistically significant difference between the means for the pre and post assessments; t(74) =8.75, p < .01, Effect Size = 1.13. Suggesting a potential to enhance learning when we engage youth in experiences that emphasize both utilitarian and inquiry-based motivations.