RESUMEN
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.
Asunto(s)
Bioquímica , Estudiantes , Bioquímica/educación , Humanos , Conocimiento , Solución de ProblemasRESUMEN
Research in science, technology, engineering, and mathematics education supports a shift from traditional lecturing to evidence-based instruction in college courses, yet it is unknown whether particular evidence-based pedagogies are more effective than others for learning outcomes like problem solving. Research supports three distinct pedagogies: worked examples plus practice, productive failure, and guided inquiry. These approaches vary in the nature and timing of guidance, all while engaging the learner in problem solving. Educational psychologists debate their relative effectiveness, but the approaches have not been directly compared. In this study, we investigated the impact of worked examples plus practice, productive failure, and two forms of guided inquiry (unscaffolded and scaffolded guidance) on student learning of a foundational concept in biochemistry. We compared all four pedagogies for basic knowledge performance and near-transfer problem solving, and productive failure and scaffolded guidance for far-transfer problem solving. We showed that 1) the four pedagogies did not differentially impact basic knowledge performance; 2) worked examples plus practice, productive failure, and scaffolded guidance led to greater near-transfer performance compared with unscaffolded guidance; and 3) productive failure and scaffolded guidance did not differentially impact far-transfer performance. These findings offer insights for researchers and college instructors.
Asunto(s)
Aprendizaje , Psicología Educacional , Ingeniería , Humanos , Matemática , Solución de ProblemasRESUMEN
Protein structure-function is a key concept in biochemistry. We used the perspective of domain-specific problem-solving to investigate students' solutions to a well-defined protein structure-function problem. We conducted think-aloud interviews with 13 undergraduate students and performed qualitative content analysis to examine the differences in the domain-general and domain-specific knowledge among correct and incorrect solutions. Our work revealed that students used domain-general and domain-specific knowledge in their problem solving. We also identified difficulties for students with the amino acid backbone, amino acid categorization, and causal mechanisms of noncovalent interactions. Using the identified difficulties, we make recommendations for the design of instructional materials targeted to improve protein structure-function problem solving in the biochemistry classroom. © 2018 International Union of Biochemistry and Molecular Biology, 46(5):453-463, 2018.
Asunto(s)
Bioquímica/educación , Solución de Problemas , Aprendizaje Basado en Problemas , Proteínas/química , Estudiantes/psicología , Humanos , Conformación ProteicaRESUMEN
With growing interest in promoting skills related to the scientific process, we studied performance in solving ill-defined problems demonstrated by graduating biochemistry majors at a public, minority-serving university. As adoption of techniques for facilitating the attainment of higher-order learning objectives broadens, so too does the need to appropriately measure and understand student performance. We extended previous validation of the Individual Problem Solving Assessment (IPSA) and administered multiple versions of the IPSA across two semesters of biochemistry courses. A final version was taken by majors just before program exit, and student responses on that version were analyzed both quantitatively and qualitatively. This mixed-methods study quantifies student performance in scientific problem solving, while probing the qualitative nature of unsatisfactory solutions. Of the five domains measured by the IPSA, we found that average graduates were only successful in two areas: evaluating given experimental data to state results and reflecting on performance after the solution to the problem was provided. The primary difficulties in each domain were quite different. The most widespread challenge for students was to design an investigation that rationally aligned with a given hypothesis. We also extend the findings into pedagogical recommendations.
Asunto(s)
Rendimiento Académico , Bioquímica/educación , Solución de Problemas , Estudiantes , Humanos , Reproducibilidad de los ResultadosRESUMEN
Expression of the MADS domain transcription factor Myocyte Enhancer Factor 2 (MEF2) is regulated by numerous and overlapping enhancers which tightly control its transcription in the mesoderm. To understand how Mef2 expression is controlled in the heart, we identified a late stage Mef2 cardiac enhancer that is active in all heart cells beginning at stage 14 of embryonic development. This enhancer is regulated by the NK-homeodomain transcription factor Tinman, and the GATA transcription factor Pannier through both direct and indirect interactions with the enhancer. Since Tinman, Pannier and MEF2 are evolutionarily conserved from Drosophila to vertebrates, and since their vertebrate homologs can convert mouse fibroblast cells to cardiomyocytes in different activator cocktails, we tested whether over-expression of these three factors in vivo could ectopically activate known cardiac marker genes. We found that mesodermal over-expression of Tinman and Pannier resulted in approximately 20% of embryos with ectopic Hand and Sulphonylurea receptor (Sur) expression. By adding MEF2 alongside Tinman and Pannier, a dramatic expansion in the expression of Hand and Sur was observed in almost all embryos analyzed. Two additional cardiac markers were also expanded in their expression. Our results demonstrate the ability to initiate ectopic cardiac fate in vivo by the combination of only three members of the conserved Drosophila cardiac transcription network, and provide an opportunity for this genetic model system to be used to dissect the mechanisms of cardiac specification.