Advancing Equity in STEM: The Impact Assessment Design Has on Who Succeeds in Undergraduate Introductory Chemistry

An Asynchronous Chemistry-in-biology Intervention Improves Student Content Knowledge and Performance in Introductory Biology

Introductory biology is a gateway course for majors and other science, technology, engineering, and mathematics (STEM) disciplines. Despite the importance of chemistry content knowledge for understanding biology, the relationship between chemistry knowledge and prior coursework and biology course performance is understudied. We used an opportunity gap framework to investigate the extent to which there were opportunity gaps in prior chemistry coursework and knowledge and associated these gaps with subsequent equity gaps in student performance on introductory biology assessments. We also developed, implemented, and assessed an asynchronous content-based intervention to support student learning and reduce equity gaps. We collected data from ∼1800 students enrolled in seven course sections of introductory biology, including two course sections prior to implementation of the intervention and five course sections with the intervention. We identified opportunity gaps in chemistry coursework that were associated with students' performance on their first introductory biology exam. The results from this study highlight the importance of addressing chemistry concepts early in a course with sufficient support for students and an understanding of opportunity gaps.

Low-Stakes, Growth-Oriented Testing in Large-Enrollment General Chemistry 1: Formulation, Implementation, and Statistical Analysis

We formulate an alternative to high-stakes examinations that is designed to help students grow, and we describe its implementation in a large-enrollment General Chemistry 1 class. In our alternative grading approach, students complete weekly assessments. Each assessment has four items that are aligned to explicit learning objectives and a level in Marzano's taxonomy, retrieval, comprehension, analysis, and knowledge utilization, which can be used by students and instructors to gauge the progression of student learning. Proficiency-based grading and multiple attempts reduce the stakes of the assessments. Unique assessments are generated through a computational infrastructure that draws question stems from an item bank and further randomizes quantities, elements, compounds, reactions, spectra, Lewis structures, orbitals, etc. in the questions. Nearly all assessment items require student-generated responses and cover a complete General Chemistry 1 curriculum. We interpret Marzano's taxonomy in the General Chemistry context and outline the structure of the learning objectives, cognitive levels, assessment schedule, and grading scheme. Item response theory (Rasch analysis) validates the theoretical framework and indicates that assessment items are high quality. Students demonstrate improvement through assessment retakes, and they report that the system motivates them to study and learn.

Undergraduate Biology Lecture Courses Predominantly Test Facts about Science Rather than Scientific Practices

Scientific practices are the skills used to develop scientific knowledge and are essential for careers in science. Despite calls from education and government agencies to cultivate scientific practices, there remains little evidence of how often students are asked to apply them in undergraduate courses. We analyzed exams from biology courses at 100 institutions across the United States and found that only 7% of exam questions addressed a scientific practice and that 32% of biology exams did not test any scientific practices. The low occurrence of scientific practices on exams signals that undergraduate courses may not be integrating foundational scientific skills throughout their curriculum in the manner envisioned by recent national frameworks. Although there were few scientific practices overall, their close association with higher-order cognitive skills suggests that scientific practices represent a primary means to help students develop critical thinking skills and highlights the importance of incorporating a greater degree of scientific practices into undergraduate lecture courses and exams.

Beyond active learning: Using 3-Dimensional learning to create scientifically authentic, student-centered classrooms

In recent years, much of the emphasis for transformation of introductory STEM courses has focused on "active learning", and while this approach has been shown to produce more equitable outcomes for students, the construct of "active learning" is somewhat ill-defined and is often used as a "catch-all" that can encompass a wide range of pedagogical techniques. Here we present an alternative approach for how to think about the transformation of STEM courses that focuses instead on what students should know and what they can do with that knowledge. This approach, known as three-dimensional learning (3DL), emerged from the National Academy's "A Framework for K-12 Science Education", which describes a vision for science education that centers the role of constructing productive causal accounts for phenomena. Over the past 10 years, we have collected data from introductory biology, chemistry, and physics courses to assess the impact of such a transformation on higher education courses. Here we report on an analysis of video data of class sessions that allows us to characterize these sessions as active, 3D, neither, or both 3D and active. We find that 3D classes are likely to also involve student engagement (i.e. be active), but the reverse is not necessarily true. That is, focusing on transformations involving 3DL also tends to increase student engagement, whereas focusing solely on student engagement might result in courses where students are engaged in activities that do not involve meaningful engagement with core ideas of the discipline.

Thinking and Learning in Nested Systems: The Classroom Level

Teaching and learning in college chemistry classrooms is affected by a variety of structural and psychosocial factors that influence classroom dynamics. In this second part of a two-part perspective [Talanquer et al. J. Chem. Educ.10.1021/acs.jchemed.3c00838], we review and discuss the results from research that has helped us understand the complex social and knowledge dynamics that emerge in interactive learning environments. We use this analysis to make explicit major insights about curriculum, instruction, assessment, teachers, and students gained in the past 25 years and to summarize their implications for chemistry education.

How Do Instructors Explain The Mechanism by which ATP Drives Unfavorable Processes?

Concerns regarding students' difficulties with the concept of energy date back to the 1970s. They become particularly apparent for systems involving adenosine triphosphate (ATP), which plays a central role in maintaining the nonequilibrium state of biological systems and in driving energetically unfavorable processes. One of the most well-documented misconceptions related to ATP is the idea that breaking bonds releases energy, when the opposite is true. This misconception is often attributed to language used in biology referring to the "high-energy bonds" in ATP. We interviewed chemistry, biology, and biochemistry instructors to learn how they think about and teach the mechanism(s) by which ATP is used as an energy source in biological systems. Across 15 interviews, we found that instructors relied primarily on two mechanisms to explain the role of ATP: 1) energy release, focused on ATP hydrolysis and bond energies; and/or 2) energy transfer, focused on phosphorylation and common intermediates. Many instructors shared negative and uncomfortable experiences related to teaching ATP and energy release. Based on these findings, we suggest instructional strategies that: 1) aim to ease the concerns expressed by introductory biology instructors, and 2) emphasize the role of ATP so as to support students' understanding of molecular mechanisms.

Addressing Equity Asymmetries in General Chemistry Outcomes Through an Asset-Based Supplemental Course

Undergraduate first-semester general chemistry (GC1) functions as a gatekeeper to STEM degrees, asymmetrically impacting students who are nonwhite, from lower socioeconomic groups, non-native English speakers, two-year college transfers, and first-generation in college. Nationally, just under 30% of students earn grades of D, F, or withdraw (termed DFW) in GC1; however, DFW rates are much higher for subgroups underrepresented in STEM occupations. Socioeconomic inequalities tend to increase over an individual's lifetime due to the magnification of cumulative disadvantage. Because undergraduate degrees correlate with higher employment and STEM occupations correlate with higher earnings, GC1 represents a critical path point where disparities can be interrupted. The most common strategy employed for GC1 is deficit remediation for students determined to be at risk of DFW. Unfortunately, extensive evidence demonstrates that the use of remediation strategies for GC1 does not sustain benefits for students. In this work, an asset-based approach, less prevalent in higher education than preuniversity, was employed to stress test theories about interrupting disparities in STEM education. This causal-comparative study involving 1,807 observations reports on a 1-credit asset-based supplemental course in which DFW-potential students at a minority-serving institution coenrolled during six semesters. The study outlines this intervention, its impact on GC1 outcomes, and its potential residual impact on progression to the next course in the general chemistry sequence (GC2). Descriptive and hierarchical inferential analysis of the data revealed socially important patterns. The asset-based intervention successfully attracted students with greater cumulative disadvantage. The intervention closed asymmetries between students identified as DFW-potential and ABC-potential in GC1 when a nontraditional curriculum was used but not when a traditional curriculum was used. Mixed results and contingent effects were found for the intervention's impact on subsequent course outcomes. Taking at least 11 credits in the semester of taking GC1 provided an inoculate for participants in the asset-based intervention, increasing the likelihood of passing GC2.

Participation in a High-Structure General Chemistry Course Increases Student Sense of Belonging and Persistence to Organic Chemistry

A parallel series of general chemistry courses for Life Science Majors was created in an effort to support students and improve general chemistry outcomes. We created a two-quarter enhanced general chemistry course series that is not remedial, but instead implements several evidence-based teaching practices including Process Oriented Guided Inquiry Learning (POGIL), Peer-Led Team Learning (PLTL), and the Learning Assistant (LA) model. We found that students who took enhanced general chemistry had higher persistence to the subsequent first organic chemistry course, and performed equally well in the organic course compared to their peers who took standard general chemistry. Students in the first enhanced general chemistry course also reported significantly higher belonging, although we were unable to determine if increased belonging was associated with the increased persistence to organic chemistry. Rather we found that the positive association between taking the enhanced general chemistry course and persistence to organic chemistry was mediated by higher grades received in the enhanced general chemistry course. Our findings highlight the responsibility we have as educators to carefully consider the pedagogical practices we use, in addition to how we assign student grades.

Rethinking (again) Hardy-Weinberg and genetic drift in undergraduate biology

Designing effective curricula is challenging. Content decisions can impact both learning outcomes and student engagement. As an example consider the place of Hardy-Weinberg equilibria (HWE) and genetic drift calculations in introductory biology courses, as discussed by Masel (2012). Given that population genetics, "a fairly arcane speciality", can be difficult to grasp, there is little justification for introducing introductory students to HWE calculations. It is more useful to introduce them to the behavior of alleles in terms of basic features of biological systems, and that in the absence of selection recessive alleles are no "weaker" or preferentially lost from a population than are dominant alleles. On the other hand, stochastic behaviors, such as genetic drift, are ubiquitous in biological systems and often play functionally significant roles; they can be introduced to introductory students in mechanistic and probabilistic terms. Specifically, genetic drift emerges from the stochastic processes involved in meiotic chromosome segregation and recombination. A focus on stochastic processes may help counteract naive bio-deterministic thinking and can reinforce, for students, the value of thinking quantitatively about biological processes.