Chemistry Education Research and Practice最新文献

The Beer–Lambert law is a fundamental relationship in chemistry that helps connect macroscopic experimental observations (i.e., the amount of light exiting a solution sample) to a symbolic model composed of system-level parameters (e.g., concentration values). Despite the wide use of the Beer–Lambert law in the undergraduate chemistry curriculum and its applicability to analytical techniques, students’ use of the model is not commonly investigated. Specifically, no previous work has explored how students connect the Beer–Lambert law to absorption phenomena using submicroscopic-level reasoning, which is important for understanding light absorption at the particle level. The incorporation of visual-conceptual tools (such as animations and simulations) into instruction has been shown to be effective in conveying key points about particle-level reasoning and facilitating connections among the macroscopic, submicroscopic, and symbolic domains. This study evaluates the extent to which a previously reported simulation-based virtual laboratory activity (BLSim) is associated with students’ use of particle-level models when explaining absorption phenomena. Two groups of analytical chemistry students completed a series of tasks that prompted them to construct explanations of absorption phenomena, with one group having completed the simulation-based activity prior to the assessment tasks. Student responses were coded using Johnstone's triad. When comparing work from the two student groups, chi-square tests revealed statistically significant associations (with approximately medium to large effect sizes) between students using the simulation and employing particle-level reasoning. That said, submicroscopic-level reasoning did not always provide more explanatory power to students’ answers. Additionally, we observed the productive use of a variety of submicroscopic light–matter interaction models. We conjecture that engaging with BLSim provided new submicroscopic-level resources for students to leverage in explanations and predictions of absorption phenomena.

Team-based learning (TBL) is an instructional strategy where students participate in a set of activities including, applying course concepts to real-life case studies in instructor-selected teams. Here, we describe how TBL has been incorporated into a 3rd year, large, environmental chemistry course and investigate the benefits of using this strategy. A combination of pre/post survey and coursework data were analyzed to understand: (1) What were student perceptions of TBL? (2) How did using TBL to deliver content influence student learning, measured by exam performance? (3) How did students’ team skills evolve? Post-survey results indicate that students perceived TBL as enhancing their interest in course content, creating real-world connections, and most helpful for achieving practical critical thinking skills. Student performance on TBL-related final exam items was significantly better (Mean = 73%, SD = 21%) than non TBL-related final exam items, (Mean = 65%, SD = 21%), despite the level of complexity being similar between the two categories. The pre/post survey results indicate that, as compared to the start of term, students reported being significantly more comfortable expressing opinions in group meetings (t(78) = 4.25, p < 0.001, Cohen's d = 0.48), and leading group discussions (t(78) = 3.11, p = 0.003, Cohen's d = 0.35), by the end of the term. The one-minute reflections (completed following the first and fifth TBL activities) indicated that there was a 14% increase (77% vs. 91%) in the number of students reporting on collective team decision making. This study demonstrates the wide-ranging positive impacts of TBL to student learning in a large Environmental Chemistry course all while enhancing active learning and applying chemistry concepts to relevant and real-life case studies.

This study examines how students’ conceptual and procedural knowledge of chemical equilibrium is affected by technology-supported formative assessment (TSFA) strategies. This study's embedded/nested mixed method research design was used to achieve the study's objective. A random sampling method was used to choose the sample of two intact classes for the treatment group and one intact class for the comparison group. To gather quantitative data, the chemical equilibrium conceptual test and the chemical equilibrium procedural test were adapted from the literature. The qualitative data were also gathered using semi-structured interviews and classroom observations. Descriptive statistics and one-way ANOVA were employed to analyze the quantitative data, and theme analysis was utilized to examine the qualitative data. One-way ANOVA results revealed that, in comparison to students who were taught using conventional methods and formative assessment strategies, students who were taught using technology-supported formative assessment strategies demonstrated improvements in conceptual and procedural knowledge. The results of semi-structured interviews and classroom observations also show that, when compared to students who are taught using conventional methods and formative assessment alone, students who are taught using technology-supported formative assessment strategies have a high improvement in learning outcomes of learning chemical equilibrium concepts. In conclusion, conventional methods and formative assessment alone were shown to be less successful for students’ conceptual and procedural knowledge in learning chemical equilibrium concepts than technology-supported formative assessment strategies. These results led the authors of this research to recommend that TSFA be used by chemistry teachers to enhance their students’ conceptual and procedural understanding of chemical equilibrium concepts.

‘Feedback’ is ubiquitous in life! Most people are constantly engaged in processes of generating or receiving different forms of feedback daily, across diverse facets of our lives. Whether we are being invited to complete an online poll after some form of interaction with a service provider; or seeking affirmation through social media; or simply thinking about our own thinking, these activities involve different forms of feedback process. In this editorial, I am exploring a topic that is deeply relevant to my own values and beliefs as a teacher in how best to support student learning in chemistry through feedback processes. I share recent education research that has moved the position of feedback from one of teacher-centric information transfer to one of learner-centric active learning based on developing feedback literacy. In reflecting on this position, I recognise that chemistry education research is ideally placed to build students' capacity in feedback literacy. Our community can capture and share further empirical evidence of strategies that effectively engage students in seeking, processing and acting on feedback as part of chemistry learning.

A national survey on chemistry instructional laboratories was administered to faculty members at four-year postsecondary institutions in the United States for the purpose of exploring levels of inquiry-based instruction implemented in laboratory courses. Respondents were asked to rate the level of choice their students had in deciding six key characteristics of the experiments used in their course (e.g., what research questions to explore); the more choices students get to make, the more inquiry-based instructional experience. MANOVA and post hoc analyses suggest that there are differences in the level of inquiry across chemistry course levels; lower-level courses (i.e., general chemistry and organic chemistry) implement lower levels of inquiry-based laboratory instruction compared to upper-level courses (i.e. more chemistry major-focused courses). We found no evidence of association between the level of inquiry courses and institutions’ highest chemistry degree awarded, American Chemical Society approval to award certified bachelors degrees, or external funding to transform postsecondary chemistry courses. Our study contributes to the chemical education community's growing understanding of the state of postsecondary chemistry laboratory instruction. Results further suggest that there is an opportunity for faculty members and department leaders to reflect on their instructional laboratory courses and implement more inquiry-based instructional laboratory experiences across the entirety of the postsecondary chemistry curriculum.

For the past decade, the College of Chemistry at UC Berkeley has iteratively redesigned general chemistry laboratory courses to introduce students to green chemistry concepts, while simultaneously using green chemistry as a relevant context to learn chemistry. To investigate the effectiveness of this curriculum we developed approaches to investigate student understanding of green chemistry. We adapted a constructivist educational framework to iteratively design fixed and free response items appropriate for large enrollment courses that probe student knowledge of green chemistry concepts and practices. Two free response items were designed to probe students’ ability to define green chemistry and make green chemistry decisions in the context of a case study. A set of fixed response items were designed to probe particular aspects of green chemistry knowledge that were included in the course. Together, we used these items to characterize (1) changes in student understanding of green chemistry and (2) how prior “green” knowledge impacts student learning of new green chemistry principles in the general chemistry laboratory course. Analysis of student responses indicated that, on average, students demonstrated increased green chemistry understanding after completing this green chemistry aligned laboratory course. Students were able to integrate more normative green chemistry principles in their answers and began to indicate awareness of complex interconnected systems. Because the items focused on assessing student knowledge of green chemistry, rather than their self-assessment of knowledge, they provided valuable insight regarding students’ prior green chemistry knowledge that will be used to develop future versions of the curriculum.

The importance of introducing students to mechanistic reasoning (MR) early in their schooling is emphasised in research. The goal of this case study was to contribute with knowledge on how early primary students’ (9–10 year-olds) MR in chemistry is expressed and developed in a classroom practice framed by model-based inquiry. The study focuses on the first lesson in a sequence of six that was developed as part of a design study. The teaching was designed to ensure student agency and create conditions for the students to develop, test, and evaluate simple particle models in interaction with observations cooperatively and under teacher guidance. During the lesson, students were encouraged to express their tentative explanatory models in drawing and writing, and to act as molecules to dramatize the expansion of air. A mechanistic reasoning framework based on the characterisation of system components (entities, properties, activities, organisation) was developed and used to analyse children's mechanistic reasoning. The framework included multimodal analysis of communication (speech, gestures, writing, drawing, bodily motion) and evaluation of student reasoning based on e.g., the presence of gaps in terms of explanatory black boxes or missing pieces. The results show that: (1) In model-based inquiry, young children can navigate across different representational levels in their reasoning and engage in MR; (2) children's black-boxing can be seen as an indication of epistemic work in the process of model-based inquiry; and (3) asking students to engage in multiple modes of representations support the development of student MR in model-based inquiry.

This study focuses on examining senior high-school students’ conceptual understanding and difficulties concerning electrochemistry and comparing patterns of thinking across Turkish and Indonesian contexts. The Electrochemistry Concept Questionnaire (ECQ) was applied to 516 Indonesian and 516 Turkish high school students right after the teaching of the electrochemistry topics. The ECQ contains 18 multiple-choice questions and these questions belong to five different categories: reactions occurring during electrolysis, differences between electrolytic and voltaic cells, movement of ions in voltaic cells, poles in voltaic cells, and voltaic cell reactions. At the end of the study, it was determined that both Indonesian and Turkish senior high-school students’ understanding of electrochemistry concepts was relatively weak and they shared common difficulties concerning electrochemical concepts. While there was no significant difference between the average scores of the students from both countries on the test, it was determined that there were some significant differences on the basis of questions. It has been concluded that students from both countries have alternative conceptions similar to those determined in previous studies such as “during electrolysis, the electric current produces ions” and “electrons migrate through the solution from one electrode to the other”. At the end of the study, the reasons for the similar results and the significantly different results for the students of the two countries to comprehend electro-concepts were discussed.

Chemish – the scientific language of chemistry – is crucial for learning chemistry. To help students acquire the competencies to understand and use Chemish, chemistry teachers need to have a sound knowledge of teaching and learning Chemish: Pedagogical Scientific Language Knowledge (PSLK). But still, despite the importance of this knowledge, the question remains what exactly it is. Based on a model for science teachers’ PSLK developed through a systematic review, this study seeks to validate the developed model by interviewing experienced chemistry teachers, filling the model with more detail, and examining further and systematising chemistry teachers’ PSLK. Therefore, semi-structured interviews with 19 German secondary chemistry teachers are conducted. The interviews are analyzed both deductively using the results of the systematic review and inductively following the approach of Grounded Theory. Finally, the elements of PSLK resulting from the systematic review, as they are knowledge of (i) scientific language role models, (ii) the development of the concept before the development of the scientific language, (iii) making scientific terms and language explicit, (iv) providing a discursive classroom, (v) providing multiple resources and representations, (vi) providing scaffolds for scientific language development, (vii) communicating expectations clearly, and (viii) specific methods and tools for teaching and learning the scientific language, could be validated and described in more detail, and even new elements, as they are the knowledge of (ix) the motivation when learning scientific language as well as (x) the knowledge of lesson preparation and follow-up, could be identified and described through the interviews. Furthermore, elements influencing the development of and PSLK itself are characterized. Implications to foster Pedagogical Scientific Language Knowledge during teacher preparation will be given.

This study aimed to analyze second-semester organic chemistry students’ problem-solving strategies, specifically focusing on the resources activated while solving problems on E2, E1, and E1cB elimination reactions. Using the theoretical framework by Elby and Hammer, we defined a resource as a unit of information used in the problem-solving process. The resources activated to solve elimination reaction problems were probed using a mixed-methods approach using survey assessments and think-aloud interviews. The data were analyzed quantitatively and qualitatively following a validated set of scoring criteria. The results align with existing findings that students focus on surface-level structural information and use resources that have been repetitively emphasized over multiple semesters. Resources related to acid–base chemistry were activated more often than reaction-specific resources, such as conformational analyses or carbocation rearrangements. Although acid–base resources aid students in successfully analyzing reaction mechanisms, additional resources must be activated to rationalize specific mechanisms and to explain the products formed. This calls for instructors to provide formative and summative assessments that evaluate the many resources required to elucidate elimination reaction mechanisms and product stereochemistry.