Chemistry Education Research and Practice最新文献

This study focuses on examining the mental models of 11th and 12th-grade students attending a science high school in Turkey regarding the concept of the electron cloud. The study involved 72 students and employed the case study method. The precondition for selecting the sample was that the students had covered the unit on modern atomic theory in their chemistry classes. The concept of the electron cloud chosen for the study is integrated into the units of “Atom and Periodic System” and “Modern Atomic Theory.” To guide the research questions, the progression of the lessons and activities within the unit were observed in three-week intervals across different classes taught by the participating teacher. Research data were collected using a data collection tool consisting of 7 open-ended questions, considering the high school chemistry course objectives. The research questions were prepared in three categories: conceptual, relational, and visual. A rubric was developed for data analysis, and codes corresponding to levels of understanding were determined. At the end of the evaluation, three mental models were identified: the electron cloud model, the hybrid/synthesis electron cloud model, and the primitive model. For these models, eight mental model categories have been determined: fully scientific, partially scientific, conceptual, relational, conceptual–relational, conceptual-visual, relational-visual, and incompatible. At the conclusion of the study, only 5.56% of students provided answers at the scientific understanding level for all categories, placing them in the full scientific model category under the electron cloud model. 16.67% of students fell into the partial scientific model category, while 75.29% demonstrated a hybrid/synthesized electron cloud model. A small portion, 2.78%, adopted a primitive model.

Thinking about knowledge and knowing (i.e., epistemic cognition) is an important part of student learning and has implications for how they apply their knowledge in future courses, careers, and other aspects of their lives. Three classes of models have emerged from research on epistemic cognition: developmental models, dimensional models, and resources models. These models can be distinguished by how value is assigned to particular epistemic ideas (hierarchy), how consistent epistemic ideas are across time and/or context (stability), and the degree to which people are consciously aware of their own epistemic ideas (explicitness). To determine the extent to which these models inform research on epistemic cognition in chemistry education specifically, we reviewed 54 articles on undergraduate chemistry students’ epistemologies. First, we sought to describe the articles in terms of the courses and unit of study sampled, the methods and study designs implemented, and the means of data collection utilized. We found that most studies focused on the epistemic cognition of individual students enrolled in introductory chemistry courses. The majority were qualitative and employed exploratory or quasi-experimental designs, but a variety of data collection methods were represented. We then coded each article for how it treated epistemic cognition in terms of hierarchy, stability, and explicitness. The overwhelming majority of articles performed a hierarchical analysis of students’ epistemic ideas. An equal number of articles treated epistemic cognition as stable versus unstable across time and/or context. Likewise, about half of the studies asked students directly about their epistemic cognition while approximately half of the studies inferred it from students’ responses, course observations, or written artifacts. These codes were then used to infer the models of epistemic cognition underlying these studies. Eighteen studies were mostly consistent with a developmental or dimensional model, ten were mostly aligned with a resources model, and twenty-six did not provide enough information to reasonably infer a model. We advocate for considering how models of epistemic cognition—and their assumptions about hierarchy, stability, and explicitness—influence the design of studies on students’ epistemic cognition and the conclusions that can be reasonably drawn from them.

A Doctor of Philosophy (PhD) is defined as the highest achievable degree and represents the completion of a specialized mentored project. Concerningly, graduate programs are structured in ways that can lead to inequities that exclude graduate students based on race, class, gender, ability, and additional intersecting social locations. Drawing from Yuval-Davis' framework on the politics of belonging and Porter et al.'s institutional critique methodology, the goal of the qualitative study was to examine how a chemistry graduate program fosters the professional development of its students through the graduate student milestones (admissions, preliminary exams, coursework, candidacy exam, seminar, and dissertation defense). The data comprised of documents such as the 2019 graduate student handbook and information from the departmental website, along with interviews involving faculty (N = 5), staff (N = 3), and administrators (N = 2) who served as policy agents. Findings highlight how misalignment within the admissions, preliminary exam, and candidacy milestones can create boundaries for belonging. In contrast, the seminar milestone had alignment that contributed to belonging while the coursework and dissertation defense milestones had ambiguous alignment that contributed to belonging. After gathering and analyzing the data, I collaborated with a team at the university's Department of Chemistry to revise the preliminary exam and candidacy exam milestones, aiming to enhance their inclusivity. Overall, this study offers implications for structuring chemistry graduate programs and STEM programs broadly.

Chemistry is often daunting for college students, contributing to high attrition rates in STEM majors. This study explored students' perceptions of the challenges in studying chemistry, including task effort and emotional costs. We examined how these perceptions, along with goal approaches, impact academic performance and retention in general chemistry. Utilizing cluster analysis of survey data and content analysis from student interviews, we investigated students’ profiles of perceived cost and goal approaches and how these related to the course performance and retention. Our analysis revealed that students who experienced lower perceived costs and were able to focus more on their mastery goals, tend to perform better, and persist in the course at higher rates. Conversely, students who perceived higher costs tend to drop the course more frequently, viewing chemistry as irrelevant to their future goals. These students prioritized performance goals over mastery, resulting in poorer performance. These results suggest that by addressing students’ perceived costs through interventions, students may focus more on their mastery goals, consequently improving their learning and understanding of the material.

Our article “What resources do high school students activate to link energetic and structural changes in chemical reactions? – A qualitative study” was recently commented on by Keith Taber. In his comment he focuses on the dominant role of the octet rule in students' reasoning and suggests that students rely on an octet framework. In the first part of this response, Taber's argument about the pervasive inappropriate use of the octet rule is supported by empirical evidence. Re-analysis of the data confirms that students often seem to assume initial atomicity, use anthropomorphic language, and closely associate the octet rule with stability. These points make the octet rule a convenient answer for students to fill the “explanatory vacuum” often left in chemistry education, e.g. for explaining the driving force of reactions. In the second part, we discuss how these observations might be rationalized. Rather than a static misconception perspective, we suggest that student's application of the octet rule can be viewed from a dynamic, resource-oriented view of learning. Three examples are introduced to illustrate the variety in students’ applications of the octet rule. For a better understanding, more detailed research on how students really think and learn about the octet rule and energetics is necessary.

Despite representations’ central role in conveying chemical phenomena, mastering them is not trivial, given the wide variety of different conventions to interpret and use them. Furthermore, instructional approaches and materials may overlook explicit discussion on how students should reason with representations. To gather evidence that could guide improvements in teaching strategies and the creation of more effective instructional materials, we explored how students use Lewis structures to make inferences about stability. Through interviews with twenty-eight organic chemistry students, we have captured a range of resources that they employed, including the features of Lewis structures they paid attention to, the conceptual resources they activated, and the sophistication of their explanations. We found that students referenced all the explicit features of the provided Lewis structures but primarily attributed stability to the unique eye-catching features of each representation. Importantly, the surface features to which students attended impacted the conceptual resources they activated and their reasoning. Specifically, some students misapplied chemical principles to make justifications that fit their correct or incorrect claims about stability. Moreover, students primarily relied on lower-level reasoning and heuristics when constructing explanations. These findings underscore the importance of probing student reasoning so that instruction and assessments can be tailored to enhance students' ability to effectively use representations to reason about chemical phenomena. By understanding the reasoning patterns students adopt, educators can develop targeted strategies that promote deeper understanding and productive use of chemical representations.

The range of abstract concepts encountered when learning chemistry and the inability of students to make connections between the macroscopic, sub-microscopic, and symbolic representations, used in chemistry teaching, are believed to be the main reasons for students’ difficulty when learning chemistry. Prediction and determination of molecular geometry using the theory of valence shell electron pair repulsion (VSEPR) is a sample of the abstract concept that is hard to understand by students who learn chemistry. Students may comprehend these ideas better if the learning process is supplemented with cutting-edge, interactive learning aids. To address the conceptual difficulties that students encounter when learning how to predict the shapes of molecules, a card game (MGCards) has been developed which is supported by simple molecular model building (MMB). The card game allows students to work through the steps required to predict the shape of a molecule in an engaging format. The student learning process is supported by feedback at all stages (if students make a mistake, they receive hints that will help them in the next step of the game). Action research with qualitative methods has been used to design, develop, and evaluate the MGCards. The MGCards and MMB were piloted at the University of Leicester with year one Natural Sciences students and modified based on the feedback received. Both MGCards and MMB were then used as part of the first-year chemistry education programme at Tanjungpura University in Indonesia. The findings of students’ answer analysis (pre- and post-test) in both cycles showed that students had a better understanding after learning with MGCards and MMB. The positive feedback for MGCards and MMB confirmed that these resources were effective in delivering an engaging learning experience. The results suggest that MGCards and MMB play a significant role in enhancing students’ understanding while also keeping them engaged.

Past research repeatedly revealed students’ struggles to understand chemical equilibria, especially concerning their dynamic nature. Black-box simulations have proven to be helpful here. However, the effect is strongly dependent on the quality of teaching, the design principles of which are not yet fully known. One aspect of debate concerns the nature of supportive learning tasks, which require students to activate, construct and reflect on their mental models to foster conceptual understanding. In this paper, we investigate how drawing-assisted simulation-based learning promotes conceptual understanding of chemical equilibria in comparison to single-choice tasks. Both types of supporting tasks involve simulation-based activities according to the German instructional design SIMMS (Simulation-basedInstruction forMentalModelling inSchool), which requires students to construct their own explanations and predictions on a chemical system before exploring it via molecular dynamics simulations and revising their explanations and predictions retrospectively. In a quasi-experimental intervention study with 174 German high school students of ten chemistry courses (tenth grade), two treatment groups (drawing group and single-choice group) were compared with a control group, assessing the progress in conceptual understanding during simulation-based learning via drawings and explanations as well as pre- and post-intervention via questionnaire. Our findings reveal similar effects of drawing tasks and elaborate single-choice tasks on conceptual understanding of chemical equilibria. For equilibrium dynamics specifically, simulation-based settings featuring drawing tasks seem to be slightly more effective than simulation-based settings featuring elaborate single-choice-tasks in fostering understanding. What is more, simulation-based settings on the divergent phenomenon of Le Chatelier (where different final states emerge from the same initial state, depending on the nature of external perturbation) seem to be more efficient than those on the convergent nature of chemical equilibria (where several initial states with different educt/product ratios yield the same final state in equilibrium) in fostering student understanding irrespective of the mode of the supportive learning task.

Recently, scholars have suggested a co-design collaboration with instructors and students to effectively implement formative assessment (FA) practices because it ensures a high-quality design that considers users’ needs, values, and goals in a specific learning context. This study examines the effect of co-designed FA practices, in which preservice science teachers (PSTs) are co-designers of FA practices, on promoting their conceptual understanding of chemistry topics in a first-year undergraduate chemistry laboratory course. Sixteen randomly selected PSTs participated in the study for two consecutive semesters. At the end of the first semester, a co-design of the FA practices was developed collaboratively with the PSTs upon the approach of conjecture mapping. Then, the second semester was devoted to examining the impact of the co-design-based FA environment on overcoming the PSTs’ alternative conceptions regarding selected four chemistry laboratory topics: thermochemistry, chemical kinetics, chemical equilibrium, acids and bases. This study employed a conversion mixed research design. To evaluate the co-design-based FA practices, PSTs’ alternative conceptions were identified through pre- and post-laboratory concept maps. The results obtained from both qualitative and quantitative data analyses showed that implementing the co-designed FA practices had a significant impact on overcoming most of the alternative conceptions held by the PSTs in all topics of laboratory investigations. This study strongly implies the inclusion of undergraduate students as active co-participants of the iterative reasoning process of the FA design to promote their understanding of chemical concepts in laboratory courses.

Providing students with feedback on their performance is a critical part of enhancing student learning in chemistry and is often integrated into homework assignments, quizzes, and exams. However, not all feedback is created equal, and the type of feedback the student receives can dramatically alter the utility of the feedback to reinforce correct processes and assist in correcting incorrect processes. This work seeks to establish a ranking of how eleven different types of testing feedback affected student retention or growth in performance on multiple-choice general chemistry questions. These feedback methods ranged from simple noncorrective feedback to more complex and engaging elaborative feedback. A test-retest model was used with a one-week gap between the initial test and following test in general chemistry I. Data collection took place at multiple institutions over multiple years. Data analysis used four distinct grading schemes to estimate student performance. These grading schemes included dichotomous scoring, two polytomous scoring techniques, and the use of item response theory to estimate students’ true score. Data were modeled using hierarchical linear modeling which was set up to control for any differences in initial abilities and to determine the growth in performance associated with each treatment. Results indicated that when delayed elaborative feedback was paired with students being asked to recall/rework the problem, the largest student growth was observed. To dive deeper into student growth, both the differences in specific content-area improvement and the ability levels of students who improved the most were analyzed.