Chemistry Education Research and Practice最新文献

Engaging in the practice of modeling is one of the core skills identified in the Next Generation Science Standards for K-12 Science Education. Drawing on the findings of fifty years of chemical education research on students’ comprehension of atomic theory and the nature of matter, we argue that student's capacity to model abstract chemical phenomena is important to acquire a deeper conceptual understanding. In this project, we explored how the knowledge of what counts as a scientific model is structured across six modeling dimensions in undergraduate general chemistry students and how that perception interplays with their interpretation of different atomic models. Analysis of semi-structured interviews shows that students possess relatively unsophisticated and unstable knowledge of the nature of scientific models. However, we observed a temporal improvement when their ideas are situated in a context over the course of the interview. Also, students interestingly invoked different ideas to justify the most accurate way of representing the atom, falling back on their perceptions of what serves as a good scientific model. These results have implications for supporting student engagement in the practice of modeling in general chemistry, specifically, when external feedback would be useful for supporting learners in integrating their content knowledge with their modeling knowledge.

Practical laboratory training is a cornerstone of education in all chemistry-related disciplines at universities. The primary goal is to teach students the correct execution of fundamental laboratory practical, which serves as a foundation for more complex, specialized techniques that are crucial for their professional careers. Laboratory practice can be challenging to master, as it requires the seamless integration of theoretical knowledge with practical application. Students often struggle to comprehend these methods and to identify key information during their studies, which was the key issue that this study focused on. To address the main research question, it was necessary to produce highly effective instructional videos that identified critical steps, which students often overlook, leading to incorrect execution of fundamental laboratory practical. In the first part of the study, these critical steps were identified by instructors of laboratory practical in first-year university students for two basic techniques: filling a volumetric flask in a pH experiment and vacuum filtration using a Büchner funnel. The problematic steps were then incorporated into the creation, filming, editing, addition of effects, and voice-over commentary for the aforementioned techniques. These specially tailored videos were integrated into the curriculum and assessed for their effectiveness in addressing the identified critical steps. The results clearly indicate a significant improvement in the execution of both techniques, with students better recognizing the important steps, and previously incorrect steps being minimized. The incorporation of these customized videos into the curriculum was also supported by the students themselves. Our results suggest that the integration of theoretical knowledge and practical skills is the key factor for success in appropriate laboratory practice and the understanding of individual laboratory techniques. Multimedia materials can assist students in better comprehending the described steps through visualization, thereby reinforcing their theoretical knowledge.

Reimagining laboratory education in chemistry can help address demands to revitalize the undergraduate chemistry curriculum. In doing so, we can help students think like scientists and connect chemistry to other disciplines. Historically, undergraduate laboratories were taught through expository experiments coupled with traditional lab reports. However, these practices do not allow for constructive alignment of the curriculum, because the assessments target the cognitive domain of learning while the learning outcomes and class activities target the psychomotor domain. This lack of alignment also limits meaningful learning in the laboratory, at the heart of the cognitive, affective, and psychomotor domains. This review summarises some recent innovations in course design and assessments for undergraduate level laboratory courses. Overall, we aspire to lower the activation energy barrier for educators to find and implement curricular reforms in laboratory education that are constructively aligned within their course. We structure this review under the major learning outcomes of laboratory instruction, defined by Reid and Shah: (1) linking cognitive and psychomotor domains; (2) developing practical skills; (3) designing experiments; and (4) improving transferable skills, which are further separated into scientific writing, oral communication, and peer learning.

Buy-in has been described as the series of judgements students make when deciding to engage with a pedagogical practice. Buy-in to pedagogical practices is known to have a meaningful impact on students’ engagement in learning environments, making it a construct of interest for researchers and practitioners. This study develops a measure of student buy-in to faculty defined laboratory learning goals by adapting an existing measure which operationalizes the construct in terms of Exposure, Persuasion, Identification, and Commitment (EPIC). The adapted measure presented in this study, deemed the EPIC-LaG (Laboratory Goals), was developed using learning goals for general and organic chemistry laboratory courses and psychometrically evaluated. Evidence related to response process indicated that students were interpreting and responding to EPIC-LaG items as intended. Structural validity evidence provided support for the unidimensional constructs of Exposure, Persuasion, Identification, and Commitment, as well as for the structural model relating the constructs. Single administration reliability evidence provided support for the internal consistency of the items. Finally, evidence of scalar measurement invariance was found for each group in the study, demonstrating the generalizability of the structural model across groups, which provides support for comparisons made between them. When comparisons were investigated, differences in buy-in pathways were identified between general and organic chemistry laboratory courses, and between ‘cookbook’ and argument-driven inquiry style general chemistry laboratory courses. This study provides psychometric evidence to support the interpretation of EPIC-LaG data and serves as a foundation for others interested in adapting the EPIC-LaG to investigate students’ buy-in to their laboratory learning goals.

Chemical kinetics is a vital yet conceptually abstract, mathematically demanding, and often challenging topic for secondary school students, necessitating innovative instructional approaches to improve conceptual understanding, foster real-world relevance, and strengthen problem-solving skills. This study examined the impact of integrating Problem-Based Learning (PBL) supported by mobile technology and structured scaffolding on students’ conceptual learning of chemical kinetics in non-governmental secondary schools in Addis Ababa, Ethiopia. A mixed-methods intervention research design was employed, involving three instructional groups: (1) PBL with mobile technology and scaffolding, (2) PBL with scaffolding alone, and (3) conventional lecture-based instruction. The instructional content addressed core topics including reaction rates, factors affecting rates, rate laws, and graphical interpretation of rate data. Quantitative data were collected through pre- and post-tests, with analyses providing evidence supporting the validity of the data for this specific population, and analyzed using Analysis of Covariance (ANCOVA). Qualitative data were gathered through semi-structured interviews and classroom observations to capture students’ engagement levels, collaborative learning experiences, and perceptions of the instructional strategies. Post-test findings showed a statistically significant instructional effect (p < 0.001), with the PBL with mobile technology and scaffolding group achieving the highest mean score (M = 44.24), followed by the PBL with scaffolding group (M = 37.03), and the lecture-based group (M = 31.00). Qualitative findings highlighted enhanced student engagement, collaboration, and problem-solving confidence, with mobile simulations helping make abstract reactions more concrete. A post hoc analysis further confirmed the robustness of the intervention effect across subgroups. The study concludes that integrating PBL with mobile technology and scaffolding offers an effective instructional model for improving conceptual understanding in chemical kinetics and recommends expanding access to mobile learning tools and incorporating technology-enhanced PBL in science curricula.

Students in Ethiopian secondary schools frequently encounter persistent difficulties in understanding complex chemistry concepts such as chemical kinetics, largely due to the prevalence of teacher-centered, lecture-based instructional approaches. This study examined the effectiveness of Socratic questioning as a pedagogical strategy to enhance Grade 11 students’ conceptual understanding of chemical kinetics in non-governmental secondary schools in Addis Ababa. Anchored in a constructivist epistemology and employing a pragmatic, mixed-methods design, the research integrated quantitative quasi-experimental pre-test/post-test control group design with qualitative interviews and classroom observations. Quantitative data from 100 students (50 in the experimental group and 50 in the control group) were analyzed using ANOVA and ANCOVA. While the pre-test scores showed a modest but statistically significant difference favoring the experimental group, ANCOVA results revealed a substantial post-test performance advantage for students taught through Socratic questioning (M = 78.6, SD = 6.34) over those in the control group (M = 52.3, SD = 5.46), F(1, 97) = 489.12, p < 0.001, with a large effect size (η² = 0.83). This indicates that Socratic questioning accounted for a significant proportion of the variance in post-test outcomes, confirming its powerful impact on students’ conceptual learning. Qualitative findings from semi-structured interviews with 12 purposively selected students and classroom observations supported the quantitative results. Four core themes emerged: (1) enhanced understanding of chemical kinetics, where students described a shift from rote memorization to active conceptual reasoning; (2) increased engagement and participation, with classrooms becoming interactive, inclusive, and dialogic; (3) improvement in critical thinking skills, as students demonstrated deeper analysis, reasoning, and problem-solving abilities; and (4) empowerment and confidence, with students reporting greater academic self-efficacy, reduced fear of failure, and increased willingness to engage in learning activities. While the study demonstrates clear instructional benefits within the specific context of a four-week unit in a limited sample, its findings offer important insights into how dialogic, inquiry-driven instruction can address persistent pedagogical challenges in Ethiopian science education. It recommends integrating this approach into secondary school science classrooms while encouraging further research across varied educational settings, subjects, and longer intervention periods to explore its broader applicability and sustained impact.

This study examined the utilization and correlation of written argumentation, multiple representations, and reasoning of pre-service science teachers (PSTs) in three learning environments (normal laboratory, virtual laboratory, and mixed laboratory) based on the Science Writing Heuristic (SWH) approach. An embedded single case design was employed in the study with the sample consisting of 20 first-year PSTs. Data consisted of 262 SWH laboratory reports prepared by the PSTs in a Chemistry 1 course over one semester. The SWH laboratory reports were analyzed using rubrics in three dimensions: argument quality, multiple representations, and reasoning. Friedman, Wilcoxon and Spearman Correlation tests were used in analyzing the holistic rubric scores. The results revealed that PSTs’ use of argument, multiple levels of representation, and reasoning were parallel to each other especially in virtual and mixed learning environments. There was a significant positive correlation between argument, representation, and reasoning in each learning environment. When compared to virtual and normal lab environments, there was a statistically significant difference in favor of mixed lab in terms of argument, multiple representations, and reasoning. Additionally, incorporating writing-to-learn activities and small and whole class discussions are recommended to enhance learning.

Student difficulties with the curly-arrow model in mechanistic organic chemistry have been the subject of a great deal of research. The inclusion of curly arrow mechanisms in an organic chemistry curriculum presents an opportunity for students to develop skills in problem solving which are useful both in higher education and employment so the topic has utility beyond content knowledge. An arrows first approach to organic mechanism has been suggested as an effective teaching strategy to prevent the development of misconceptions which may undermine a student's achievement and cause difficulties with further study. Through the lens of the A-level in chemistry, a regulated national qualification covering significant mechanistic chemistry content, we have evaluated a range of evidence to explore how mechanistic organic chemistry is taught. Taking a holistic overview of the curriculum we show that many aspects of the curriculum support an arrows first approach to teaching including the implemented and assessed curriculum, both influenced by examination boards. However we also found that a much larger proportion of teaching time, effort and assessment is devoted to case-study mechanisms, generally organised by functional group. These may be memorised by students, undermining an arrows first focus. Moreover, although we found our sample of teacher respondents were generally positive about teaching the fundamentals of the curly arrow model we also found a lack of accessible classroom resources and professional development to support teaching using an arrows first approach. In light of the published aims of the A-level in chemistry, this research has implications for policy and practice in the 16–18 chemistry curriculum for educators, examination boards and regulators.

Chemistry education has begun to consider disciplinary practices as complementary to traditional instruction of content knowledge. A challenge in this, however, is that our understanding of the latter is far more developed: given a canonical question, it is more obvious to instructors whether a student's reasoning is correct than if it reflects productive approaches to sensemaking. In this study, we investigated how expert chemists approach sensemaking when challenged with a novel question. Here we focus on a prominent aspect of the results, the experts’ pervasive use of analogies, defined as explicit references to previous knowledge from other situations. The findings reinforce the importance of analogical reasoning in disciplinary expertise. Descriptions of how chemists’ reason in novel situations will help educators recognize the productivity of students’ sensemaking independent of its correctness.

This study used a graph theory-based social network analysis method to explore the cognitive knowledge structures of groups of high school students with different achievement levels on the topic of ethanol. Its aim was to provide practical suggestions for classroom-based teaching of different student groups. Semi-structured interviews were used to collect data on the ethanol knowledge of students at three different achievement levels from a high school in Shenzhen, China. Each of these three levels consisted of 23 students, for a total of 69 students. Interviews were conducted one week after the students had received ethanol instruction. Subsequently, the interview records for each student were transformed into an individual-student co-occurring phrases matrix. The co-occurring phrases matrices of the 23 students in each group were ultimately combined into a larger group co-occurring phrases matrix for evaluation using social network analysis. Data on cognitive knowledge structures were analyzed along three dimensions: structural features, content based on organizational features, and learning difficulties. The results revealed that, on the topic of ethanol, (1) the students with the highest academic achievement constructed a cognitive knowledge structure with more nodes, connections, and greater integration compared to the group with the lowest academic achievement; (2) the organization and content of the cognitive knowledge structures on ethanol differed among different student achievement levels; e.g., the node categories with the ability to control the exchange of information were more diversified in the high-achieving student group, while those of the low-achieving group were more homogeneous, and the organization of the former's cognitive knowledge structure was clearer than that of the latter; and (3) all student groups experienced learning difficulties with certain ethanol contents, including odor, symbolic representation, oxidation by strong oxidants, and structure–property linkages.