Design and Implementation of a Tool to Assess Students' Understanding of Metabolic Pathways Dynamics and Regulation

Putting the Pieces Together: Student Thinking about Transformations of Energy and Matter

Research on student thinking facilitates the design of instructional materials that build on student ideas. The pieces framework views student knowledge as consisting of independent pieces that students assemble in fluctuating ways based on the context at hand. This perspective affords important insights about the reasons students think the way they do. We used the pieces framework to investigate student thinking about the concept transformations of energy and matter with a specific focus on metabolism. We conducted think-aloud interviews with undergraduate introductory biology and biochemistry students as they solved a metabolism problem set. Through knowledge analysis, we identified two categories of knowledge elements cued during metabolism problem solving: 1) those about the visual representation of negative feedback inhibition; and 2) those pertaining to student focus on different metabolic compounds in a pathway. Through resource graph analysis, we found that participants tend to use knowledge elements independently and in a fluctuating way. Participants generally showed low representational competence. We recommend further research using the pieces perspective, including research on improving representational competence. We suggest that metabolism instructors teach metabolism as a concept, not a collection of example pathways, and explicitly instruct students about the meaning of visual representations associated with metabolism.

Development and Validation of a Four-Tier Test for the Assessment of Secondary School Students' Conceptual Understanding of Amino Acids, Proteins, and Enzymes

Previous studies noted the scantiness of diagnostic instruments for the assessment of students' understanding of fundamental biochemistry concepts. Consequently, within this study, a four-tier test for the examination of secondary school students' conceptual understanding of amino acids, proteins, and enzymes has been developed. Items in the test consist of the answer tier, the reason tier, and a confidence rating for each of these tiers. Following the three-phase development process, the final version of the test, comprising eight items, was administered to 123 students in the main study. The internal consistency of both cognitive scores and confidence ratings proved to be adequate (Cronbach's alpha values were 0.76 and 0.87, respectively) and the test-retest reliability was also satisfactory (Pearson's r value was 0.74 for the cognitive scores and 0.88 for the confidence ratings). If the correct responses to both the answer and the reason tier of items are considered, the mean score on the test was 3 out of 8 (38%). The students were more confident when producing the correct compared to the wrong answers but, overall, their confidence was not high (3.65 out of 6). Furthermore, the confidence in the incorrect answers that were provided (3.52 out of 6) indicates the presence of alternative conceptions. Such results show that the content regarding amino acids, proteins, and enzymes is conceptually challenging for the students. Therefore, the test can help secondary school teachers to uncover the students' conceptual difficulties related to this content and develop effective strategies for their remediation and prevention.

Supplementary Information

The online version contains supplementary material available at 10.1007/s11165-022-10075-5.