Arrows in Biology: Lack of Clarity and Consistency Points to Confusion for Learners

Here Is the Biology, Now What is the Mechanism? Investigating Biology Undergraduates' Mechanistic Reasoning within the Context of Biofilm Development

Understanding molecular processes and coordinating the various activities across levels of organization in biological systems is a complicated task, yet many curricular guidelines indicate that undergraduate students should master it. Employing mechanistic reasoning can facilitate describing and investigating biological phenomena. Biofilms are an important system in microbiology and biology education. However, few empirical studies have been conducted on student learning of biofilms or how students utilize mechanistic reasoning related to systems thinking to explain biofilm formation. Using mechanistic reasoning and the theory of knowledge integration as conceptual and analytical frameworks, we examined the features of 9 undergraduate biology students' mechanistic models of a specific transition point in biofilm development. From these data, we constructed a model of knowledge integration in the context of biofilms, which categorizes students' knowledge based on features of their descriptions (e.g., entities, correct connections, and the nature of connections). We found that 4 of 9 students produced a fragmented model, 4 of 9 students produced a transitional model, and 1 student produced a connected model. Overall, students often did not discuss cell-cell communication mechanics in their mechanistic models and rarely included the role of gene regulation. Most connections were considered nonnormative and lacked important entities, leading to an abundance of unspecified causal connections. We recommend increasing instructional support of mechanistic reasoning within systems (e.g., identifying entities across levels of organization and their relevant activities) and creating opportunities for students to grapple with their understanding of various biological concepts and to explore how processes interact and connect in a complex system.

Visual Literacy of Molecular Biology Revealed through a Card-Sorting Task

Visual literacy, which is the ability to effectively identify, interpret, evaluate, use, and create images and visual media, is an important aspect of science literacy. As molecular processes are not directly observable, researchers and educators rely on visual representations (e.g., drawings) to communicate ideas in biology. How learners interpret and organize those numerous diagrams is related to their underlying knowledge about biology and their skills in visual literacy. Furthermore, it is not always obvious how and why learners interpret diagrams in the way they do (especially if their interpretations are unexpected), as it is not possible to "see" inside the minds of learners and directly observe the inner workings of their brains. Hence, tools that allow for the investigation of visual literacy are needed. Here, we present a novel card-sorting task based on visual literacy skills to investigate how learners interpret and think about DNA-based concepts. We quantified differences in performance between groups of varying expertise and in pre- and postcourse settings using percentages of expected card pairings and edit distance to a perfect sort. Overall, we found that biology experts organized the visual representations based on deep conceptual features, while biology learners (novices) more often organized based on surface features, such as color and style. We also found that students performed better on the task after a course in which molecular biology concepts were taught, suggesting the activity is a useful and valid tool for measuring knowledge. We have provided the cards to the community for use as a classroom activity, as an assessment instrument, and/or as a useful research tool to probe student ideas about molecular biology.

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.

The DNA Landscape: Development and Application of a New Framework for Visual Communication about DNA

Learning molecular biology involves using visual representations to communicate ideas about largely unobservable biological processes and molecules. Genes and gene expression cannot be directly visualized, but students are expected to learn and understand these and related concepts. Theoretically, textbook illustrations should help learners master such concepts, but how are genes and other DNA-linked concepts illustrated for learners? We examined all DNA-related images found in 12 undergraduate biology textbooks to better understand what biology students encounter when learning concepts related to DNA. Our analysis revealed a wide array of DNA images that were used to design a new visual framework, the DNA Landscape, which we applied to more than 2000 images from common introductory and advanced biology textbooks. All DNA illustrations could be placed on the landscape framework, but certain positions were more common than others. We mapped figures about "gene expression" and "meiosis" onto the landscape framework to explore how these challenging topics are illustrated for learners, aligning these outcomes with the research literature to showcase how the overuse of certain representations may hinder, instead of help, learning. The DNA Landscape is a tool to promote research on visual literacy and to guide new learning activities for molecular biology.

Psychology: a Giant with Feet of Clay

The aim of the current study has been to highlight the theoretical precariousness of Psychology. The theoretical precariousness has been evidenced through a review of psychological "core-constructs" whose definitions were thoroughly searched in 11 popular introductory textbooks of psychology edited between 2012 and 2019 and in an APA dictionary of Psychology (VandeBos 2015). This analysis has shown unsatisfactory or discordant definitions of psychological "core-constructs". A further epistemological comparison between psychology and three "harder" sciences (i.e., physics, chemistry and biology) seemed to support the "soft" nature of psychology: a minor consensus in its "core" and a minor capacity to accumulate knowledge when compared to the former "harder" sciences (Fanelli in PLoS One, 5, e10068, 2010; Fanelli and Glänzel in PLoS One, 8, e66938, 2013). This comparison also seemed to support the "pre-paradigmatic" condition of psychology, in which conflicts between rival schools of thought hamper the development of a real unified paradigm (Kuhn 1970). To enter a paradigmatic stage, we propose here evolutionary psychology as the most compelling approach, thanks to its empirical support and theoretical consistency. However, since the skepticism about "grand unifying theories" is well disposed (Badcock in Review of General Psychology, 16, 10-23, 2012), we suggest that evolutionary psychology must be intended as a pluralistic approach rather than a monolithic one, and that its main strength is its capacity to resolve the nature-nurture dialectics.

Diagram comprehension ability of college students in an introductory biology course

College biology courses commonly use diagrams to convey information. These visual representations are embedded in course materials with the expectation that students can comprehend and learn from them. Educational research, however, suggests that many students have difficulty understanding diagrams and the conventions (e.g., labels, arrows) they contain. The present study evaluates biology students' ability to comprehend scientific diagrams and the diagram characteristics that affect this comprehension. Participants were students in a physiology course who completed a multiple-choice test of diagram comprehension ability (DCA) (Cromley JG, Perez TC, Fitzhugh SL, Newcombe NS, Wills TW, Tanaka JC. J Exp Educ 81: 511-537, 2013). We coded the conventions used in each test diagram and used these codes to capture the diagram characteristics of conventions and complexity. Descriptive analyses examine students' ability to understand scientific diagrams and which diagram characteristics cause the most difficulty. We also compared groups with low and high DCA scores to evaluate how students at different levels of comprehension ability are affected by diagram characteristics. Results show relatively poor DCA; the average total test score was only 69.5%. The conventions used in a diagram also affected diagram comprehension, and results show students had the most difficulty comprehending diagrams using a letter or numbering system, where arbitrary letters/numbers were used to signify objects and diagrams using cut-outs that showed cross sections and magnified interior views. Additionally, students' comprehension was higher on diagrams with higher complexity (i.e., more types of conventions used), potentially indicating students are able to take advantage of the supports that different conventions provide. Implications for instruction are identified.

Modeling in the Classroom: Making Relationships and Systems Visible

As an instructional tool, models can transform the student experience from the static to the dynamic, the flat to the 3D, and the siloed to the integrated. Few practical resources exist to help instructors transition toward model-based classroom practices. The Modeling in the Classroom evidence-based teaching guide provides instructors with a tool kit for incorporating models and modeling into their classrooms (https://lse.ascb.org/evidence-based-teaching-guides/modeling-in-the-classroom). The guide discusses the underpinnings of modeling as a core scientific practice, one that can enable student development of systems thinking skills and understanding of biological concepts. The guide describes a variety of model types, including phylogenetic trees, simulations, animations, diagrams, conceptual models, concept maps, and tactile models supported by summaries of and links to articles and resources. In this paper, we will introduce key findings describing why and how to use models in the classroom. We also describe open research questions needed to address classroom implementation, instructional design, and development of students' knowledge and skills. It is our hope that the guide will provide a suitable combination of research-based findings and practical suggestions that instructors will be supported and encouraged to thoughtfully incorporate modeling to support learning goals.

The Graph Rubric: Development of a Teaching, Learning, and Research Tool

As undergraduate biology curricula increasingly aim to provide students with access to courses and experiences that engage them in the practices of science, tools are needed for instruction, evaluation, and research around student learning. One of the important skills for undergraduate biology students to master is the selection and creation of appropriate graphs to summarize data they acquire through investigations in their course work and research experiences. Graphing is a complex skill, and there are few, discipline-informed tools available for instructors, students, and researchers to use. Here, we describe the development of a graph rubric informed by literature from the learning sciences, statistics, representations literature, and feedback and use of the rubric by a variety of users. The result is an evidence-based, analytic rubric that consists of categories essential for graph choice and construction: graph mechanics, graph communication, and graph choice. Each category of the rubric can be evaluated at three levels of achievement. Our analysis demonstrates the potential for the rubric to provide formative feedback to students and allow instructors to gauge and guide learning and instruction. We further discuss and identify potentially interesting research targets for science education researchers.

Physical models can provide superior learning opportunities beyond the benefits of active engagements

The essence of molecular biology education lies in understanding of gene expression, with subtopics including the central dogma processes, such as transcription and translation. While these concepts are core to the discipline, they are also notoriously difficult for students to learn, probably because they cannot be directly observed. While nearly all active learning strategies have been shown to improve learning compared with passive lectures, little has been done to compare different types of active learning. We hypothesized that physical models of central dogma processes would be especially helpful for learning, because they provide a resource that students can see, touch, and manipulate while trying to build their knowledge. For students enrolled in an entirely active-learning-based Cell & Molecular Biology course, we examined whether model-based activities were more effective than non-model based activities. To test their understanding at the beginning and end of the semester, we employed the multiple-select Central Dogma Concept Inventory (CDCI). Each student acted as their own control, as all students engaged in all lessons yet some questions related to model-based activities and some related to clicker questions, group problem-solving, and other non-model-based activities. While all students demonstrated learning gains on both types of question, they showed much higher learning gains on model-based questions. Examining their selected answers in detail showed that while higher performing students were prompted to refine their already-good mental models to be even better, lower performing students were able to construct new knowledge that was much more consistent with an expert's understanding. © 2018 The Authors. Biochemistry and Molecular Biology Education published by Wiley Periodicals, Inc. on behalf of International Union of Biochemistry and Molecular Biology., 46(5):435-444, 2018.