Search

Contextual features of assessments can influence the ideas students draw from and the ways they assemble knowledge. We used a mixed-methods approach to explore how surface-level item context impacts student reasoning. In study 1, we developed an isomorphic survey to capture student reasoning about fluid dynamics, a crosscutting phenomenon, in two item contexts (blood vessels, water pipes), and administered the survey to students in two different course contexts: human anatomy and physiology (HA&P) and physics. We observed a significant difference in two of 16 between-context comparisons and a significant difference in how HA&P students responded to our survey compared with physics students. In study 2, we conducted interviews with HA&P students to explore our findings from study 1. Using the resources and framing theoretical framework, we found that HA&P students responding to the blood vessel protocol used teleological cognitive resources more frequently compared with HA&P students responding to the water pipes version. Further, students reasoning about water pipes spontaneously introduced HA&P content. Our findings support a dynamic model of cognition and align with previous work suggesting item context impacts student reasoning. These results also underscore a need for instructors to recognize the impact of context on student reasoning about crosscutting phenomena.

Most of the research on student understanding of evolution by natural selection has focused on undergraduate biology courses for science majors. However, the majority of undergraduates in the United States will not enroll in a biology course for majors. In this study, we identify the extent of natural selection understanding that students acquire through an undergraduate, non-majors geology course. Using a pre/post assessment model, we administered open-response items from the Bishop and Anderson Diagnostic Instrument and a religiosity scale. Student responses were coded for inclusion and correctness of five key principles of natural selection: variation in a population, origin of variation, inheritance, fitness, and change in a population over time. The majority of students included few, if any, key principles of natural selection in their responses prior to instruction, and improvement after direct instruction in their geology course was minimal (cheetah: mean pre 1.01, mean post 1.37; salamander: mean pre 0.79, mean post 1.15). In most cases, students' self-reported religiosity was unrelated to their knowledge of natural selection. Together, our results demonstrate that in spite of instruction, non-majors geology students struggle to describe the process of natural selection using foundational principles. We encourage the continued development of cross-disciplinary educational resources for this important population to help all students, regardless of major or career path, gain a more robust understanding of evolution by natural selection.

Nuclear magnetic resonance (NMR) spectroscopy is vital to synthesis and provides rich problem-solving opportunities to organic chemistry students. Using the theories of scaffolding, interleaving, and blocking, our research systematically explores how textbooks introduce and reinforce spectral features when teaching students to solve [superscript 1]H NMR spectroscopy problems. Specifically, we investigated the [superscript 1]H NMR spectral features presented in worked examples and practice problems across four undergraduate organic chemistry textbooks. We examined the frequency and ordering of spectral features to explore how the textbooks could support scaffolded instruction. Spectral features like the number of signals and chemical shift were covered by problems more frequently, while integration was covered least. Our findings suggest that textbooks do not provide sufficient practice with all [superscript 1]H NMR spectral features. We observed no discernible pattern in how textbooks ordered spectral features of [superscript 1]H NMR in problems, indicating that there is little systematic method to the design of textbook chapters. Implications for textbook authors and editors, instruction, and research are discussed.

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.

In this qualitative study, we examined the process of active learning from the perspective of undergraduate students in a high-enrollment introductory biology class. Eight students participated in a series of five interviews throughout the semester that examined their experiences during and after class. Grades were collected for each student at regular time points throughout the semester. Here, we present in-depth case studies of four students who described profoundly different responses to the same in-class learning tasks. We particularly highlight variation in students' self-reported engagement, as engagement is thought to be a key element of successful active learning. Finally, we map each student's self-reported engagement and the grades that he or she received. In each case, we found that grades failed to capture some aspects of the active-learning experience that students found important.

Phylogenetic trees have become increasingly important across the life sciences, and as a result, learning to interpret and reason from these diagrams is now an essential component of biology education. Unfortunately, students often struggle to understand phylogenetic trees. Style (i.e., diagonal or bracket) is one factor that has been observed to impact how students interpret phylogenetic trees, and one goal of this research was to investigate these style effects across an introductory biology course. In addition, we investigated the impact of instruction that integrated diagonal and bracket phylogenetic trees equally. Before instruction, students were significantly more accurate with the bracket style for a variety of interpretation and construction tasks. After instruction, however, students were significantly more accurate only for construction tasks and interpretations involving taxa relatedness when using the bracket style. Thus, instruction that used both styles equally mitigated some, but not all, style effects. These results inform the development of research-based instruction that best supports student understanding of phylogenetic trees.

The availability of reliable evidence for teaching practices after professional development is limited across science, technology, engineering, and mathematics disciplines, making the identification of professional development "best practices" and effective models for change difficult. We aimed to determine the extent to which postdoctoral fellows (i.e., future biology faculty) believed in and implemented evidence-based pedagogies after completion of a 2-yr professional development program, Faculty Institutes for Reforming Science Teaching (FIRST IV). Postdocs (PDs) attended a 2-yr training program during which they completed self-report assessments of their beliefs about teaching and gains in pedagogical knowledge and experience, and they provided copies of class assessments and video recordings of their teaching. The PDs reported greater use of learner-centered compared with teacher-centered strategies. These data were consistent with the results of expert reviews of teaching videos. The majority of PDs (86%) received video ratings that documented active engagement of students and implementation of learner-centered classrooms. Despite practice of higher-level cognition in class sessions, the items used by the PDs on their assessments of learning focused on lower-level cognitive skills. We attributed the high success of the FIRST IV program to our focus on inexperienced teachers, an iterative process of teaching practice and reflection, and development of and teaching a full course.

Phylogenetic trees are widely used visual representations in the biological sciences and the most important visual representations in evolutionary biology. Therefore, phylogenetic trees have also become an important component of biology education. We sought to characterize reasoning used by introductory biology students in interpreting taxa relatedness on phylogenetic trees, to measure the prevalence of correct taxa-relatedness interpretations, and to determine how student reasoning and correctness change in response to instruction and over time. Counting synapomorphies and nodes between taxa were the most common forms of incorrect reasoning, which presents a pedagogical dilemma concerning labeled synapomorphies on phylogenetic trees. Students also independently generated an alternative form of correct reasoning using monophyletic groups, the use of which decreased in popularity over time. Approximately half of all students were able to correctly interpret taxa relatedness on phylogenetic trees, and many memorized correct reasoning without understanding its application. Broad initial instruction that allowed students to generate inferences on their own contributed very little to phylogenetic tree understanding, while targeted instruction on evolutionary relationships improved understanding to some extent. Phylogenetic trees, which can directly affect student understanding of evolution, appear to offer introductory biology instructors a formidable pedagogical challenge.

Mutation is the key molecular mechanism generating phenotypic variation, which is the basis for evolution. In an introductory biology course, we used a model-based pedagogy that enabled students to integrate their understanding of genetics and evolution within multiple case studies. We used student-generated conceptual models to assess understanding of the origin of variation. By midterm, only a small percentage of students articulated complete and accurate representations of the origin of variation in their models. Targeted feedback was offered through activities requiring students to critically evaluate peers' models. At semester's end, a substantial proportion of students significantly improved their representation of how variation arises (though one-third still did not include mutation in their models). Students' written explanations of the origin of variation were mostly consistent with their models, although less effective than models in conveying mechanistic reasoning. This study contributes evidence that articulating the genetic origin of variation is particularly challenging for learners and may require multiple cycles of instruction, assessment, and feedback. To support meaningful learning of the origin of variation, we advocate instruction that explicitly integrates multiple scales of biological organization, assessment that promotes and reveals mechanistic and causal reasoning, and practice with explanatory models with formative feedback.

Research in contemporary biology has become increasingly complex and organized around understanding biological processes in the context of systems. To better reflect the ways of thinking required for learning about systems, we developed and implemented a pedagogical approach using box-and-arrow models (similar to concept maps) as a foundational tool for instruction and assessment in an Introductory Biology course on genetics, evolution, and ecology. Over the course of one semester, students iteratively constructed, evaluated, and revised "Gene-to-Evolution" (GtE) models intended to promote understanding about the connections linking molecular-level processes with population-level outcomes. In practice, a successful GtE model contextualizes information provided in a case study and explains how genetic-level variation originates at the molecular level, is differentially expressed among individuals, and is acted upon by the environment to produce evolutionary change within a population. Our analyses revealed that students' ability to construct biologically accurate models increased throughout the semester. Model complexity peaked near mid-term then subsequently declined. This suggests that, with time, students were building more parsimonious models, shedding irrelevant information, and improving in their ability to apply accurate and appropriate biological language to explain relationships among concepts. Importantly, we observed the greatest relative gains in model correctness among students who entered the course with lower mean GPA. In an analysis comparing performance among achievement tritiles, lower-performing students effectively closed the achievement gap with the highest performing students by the end of the semester. Our findings support the effectiveness of model-based pedagogies for science teaching and learning, and offer a perspective on pedagogical application of modeling strategies to foster systems thinking and knowledge structuring in college-level biology. (Contains 4 tables and 6 figures.)

Biology majors often take introductory biology, chemistry, and physics courses during their first two years of college. The various and sometimes conflicting discourse about and explanations of matter and energy in these courses may contribute to confusion and alternative conceptions (those that differ from scientific consensus) in biology learners. An important area of biology education research--students' alternative conceptions--has produced a lengthy list of alternative conceptions related to students' understanding of matter and energy flow through biological systems through processes such as photosynthesis and cellular respiration. By synthesizing the research literature and conducting interviews of science faculty members, we have identified similarities and differences in matter and energy discourse and teaching in these different science disciplines. This study can help biology instructors recognize and appreciate the ways in which instructors present concepts related to energy and matter in their courses and alter their discourse and teaching practices to promote learning and minimize confusion among their students.

Biology of the twenty-first century is an increasingly quantitative science. Undergraduate biology education therefore needs to provide opportunities for students to develop fluency in the tools and language of quantitative disciplines. Quantitative literacy (QL) is important for future scientists as well as for citizens, who need to interpret numeric information and data-based claims regarding nearly every aspect of daily life. To address the need for QL in biology education, we incorporated quantitative concepts throughout a semester-long introductory biology course at a large research university. Early in the course, we assessed the quantitative skills that students bring to the introductory biology classroom and found that students had difficulties in performing simple calculations, representing data graphically, and articulating data-driven arguments. In response to students' learning needs, we infused the course with quantitative concepts aligned with the existing course content and learning objectives. The effectiveness of this approach is demonstrated by significant improvement in the quality of students' graphical representations of biological data. Infusing QL in introductory biology presents challenges. Our study, however, supports the conclusion that it is feasible in the context of an existing course, consistent with the goals of college biology education, and promotes students' development of important quantitative skills. (Contains 5 tables and 4 figures.)