From assessment to intervention: Conceptual understanding of rate and accumulation processes

This Work in Progress paper investigates how engineering students think and learn about rate and accumulation processes. Previous research found robust misconceptions about rate and accumulation processes among sophomore engineering students, leading to the development of the Rate and Accumulation Concept Inventory (RACI)^1,2. The primary motive for our developing the RACI was to provide a valid tool that teachers and curriculum developers could use to assess student mastery of rate and accumulation processes. The primary goals of the RACI are to assess (1) overall mastery of rate and accumulation concepts, (2) mastery of these concepts within particular contexts (e.g., heat flow, water flow), and (3) the prevalence of certain misconceptions related to rate and accumulation processes. Initial pilot testing of the RACI indicated persistent misconceptions across multiple contexts. Content validity evidence was developed using multiple faculty reviews of the test items. Internal consistency reliability was assessed on an earlier version of the RACI using the Kuder-Richardson Formula 20. This yielded a value of 0.77 for the instrument and ranges of 0.64 to 0.76 for the three contextual categories². Several efforts are underway to improve the validity, reliability, and fairness of the RACI. A thorough taxonomy of the RACI has been developed to synthesize the understandings and abilities that are included in the RACI question items. Initial findings from this process led to the addition of question items. Methods suggested by the Evidentiary Validity Framework³ are used to assess the validity of each of the primary goals of the RACI. Additional pilot tests using a range of student populations will provide further reliability analysis of the RACI. These tests are being conducted in both sophomore and junior level classes in a variety of disciplines, including civil and environmental engineering, mechanical engineering, and chemical engineering. This research also includes the development of instructional methods with the aim of correcting student misconceptions identified by the RACI. Inquiry-based learning activities were designed using variation theory⁴ to challenge students' conceptual understanding of rate and accumulation processes across multiple contexts. Activities include the use of toy bricks to construct rate and accumulation graphs. These activities will be tested in a required sophomore civil and environmental engineering course. The success of these activities will be measured using formative assessments and pre-post course RACI scores. An observation protocol will also be used to assess students' responses to the class activities⁵.