Search for: All records

Student motivation within a STEM course is dependent on their perceived relevance and utility of the topics learned. This paper presents an Informative Utility Value Intervention (IUVI) designed to promote perceptions of utility. The IUVI was designed as a series of assignments for general chemistry students in large lecture courses, but the method can be adapted to other science disciplines. The intervention begins by establishing a baseline of students’ utility-value of chemistry then scaffolds new connections to their field of interest. The scaffold includes directing students to published articles demonstrating real-world connections between topics they are learning and their career interests. Student responses indicate they were able to make connections between the topic and their career interests and they perceived the articles as relevant to their career interests. 

Chemistry instruction should provide students a rationale for appreciating chemistry as a useful discipline, which is a particular challenge given the diverse student interests within introductory chemistry courses. In this study, we introduce and evaluate an interactive assignment, called an Informative Utility Value Intervention (IUVI), meant to improve students’ perceptions of the utility of chemistry. IUVI provides students with web-based articles describing how chemistry topics are relevant to the students’ chosen career interests. IUVI was administered to second-semester general chemistry students with a quasiexperimental study design in which one section from each instructor was given the intervention, and pre-intervention measures were used to account for potential differences between groups. The results indicate that students who received the intervention reported higher perceptions of the utility of chemistry at the end of the semester and higher scores on a common final exam than students who did not receive the intervention. Results from a structural equation model indicated the IUVI was associated with improved utility perceptions and final exam scores; however, these improvements were potentially independent of each other. Therefore, the theoretical explanation that improved perceptions of utility value resulted in improved academic performance could not be supported. Overall, IUVI offers an effective and highly portable intervention which can be adopted and adapted by instructors to promote students’ utility perceptions of chemistry. 

Electrostatic potential maps (EPM) have the potential to support organic chemistry students in seeing reaction mechanisms through the perspective of electrostatic attraction. Prior to any pedagogical changes, foundational knowledge on how students use EPMs in particular contexts would be needed to inform how to integrate EPMs into instruction. This study describes an exploration into how organic chemistry students use EPMs during two card sort tasks. Seventeen undergraduate organic chemistry students participated in an interview that included an open and closed card sort. The interviews were inductively coded to identify students’ usage of EPMs, and usage change based on the open sort compared to the closed sort. Viewed from a resources framework, this study demonstrated how students’ use of EPMs shifted depending on the task structure. Variations were observed both among students and within students between tasks in terms of whether EPMs were utilized and when utilized whether information from EPMs were used in isolation or integrated with other chemistry concepts. The results of this study imply that more formal integration of EPMs into instruction and assessment would be needed for students who did not use EPMs. Instruction that models and assesses translation of representations may begin activating a more integrated perspective of EPMs which could be productive for students who had an isolated use of EPMs. The introduction of EPMs independent of specific chemistry tasks (e.g.during a general introduction of molecular representations) could lead some students to focus only on explicit features of the EPM representation and not tie features of the representation to their existing chemical knowledge. 

Reaction mechanisms are a difficult and foundational topic students encounter in organic chemistry. Consequently, students often memorize when attempting to learn the array of organic reactions. While interventions have been offered to encourage mechanistic reasoning as an alternative approach, a deeper struggle pertaining to students’ comprehension of the underlying chemical principles driving reaction mechanisms is still prevalent. In this study, electrostatic potential maps (EPMs) were explored as a tool students could use to reason with some of these principles to predict and explain the outcomes of a reaction. Through semistructured interviews, 19 students’ sense-making strategies were recorded and analyzed to uncover how they used the features of EPMs with concealed atomic identities and how they reconciled their answers once the identities were made explicit. Analysis revealed that the absence of atomic identities generated approaches centered around electron densities and their utility in predicting reaction mechanisms and outcomes. As the atomic identities were revealed, the majority of participants reverted to memorized mechanisms, while six participants attempted to relate the atomic identities to the interactions of the electron densities. These findings suggest utility in implementing EPMs in the organic chemistry curriculum and offer a feasible intervention to promote sense-making when students reason with organic reactions. 

Instructional materials in organic chemistry include a wide variety of representations, such as chemical formulas, line-angle diagrams, ball-and-stick diagrams, and electrostatic potential maps (EPMs). Students tend to focus on explicit features of a representation while they are reasoning about chemical concepts. This study examined the affordances of electrostatic potential maps in students’ approaches when the maps were integrated into four foundational organic chemistry problems using an experimental design approach. First-semester organic chemistry students were surveyed from two different institutions, where they made predictions and explained their reasoning behind identifying an electrophilic site, predicting the product, selecting the faster reaction, and classifying a mechanism. Students were randomly assigned to one of four surveys that differed by the representation they were given for the prompts: chemical formula, line-angle diagram, ball-and-stick diagram, and EPM. Responses from students with EPMs were analyzed and compared to responses from students with the non-EPM representations. Results indicated that students with EPMs had higher performance depending on the problem. They were also more likely to cite electronic features such as electron density, nucleophilicity, etc., and were more likely to use causal reasoning in their explanations. This study offers evidence in support of affordances of EPMs in promoting students’ use of electronic features and causal reasoning. This evidence adds to the chemistry education literature by offering a potential means for promoting students’ use of electronic features and causal reasoning by incorporating EPMs into assessment items. Implications for instruction include using EPMs in both instruction and assessment as a tool to help students build skills around invoking electrostatics and causal reasoning to solve problems in organic chemistry. 

Representations in chemistry are the tools by which students, instructors, and chemists reason with chemical concepts that are abstract. Although representations are regularly used within the chemistry classroom, there is more to uncover regarding the ways students interact with representations when given chemistry tasks. This study aimed to address this gap in knowledge. In this study, eighteen students enrolled in second semester general chemistry were recruited for data collection. Semi-structured interviews were utilized to observe how students approached a similar set of dipole–dipole interaction tasks when given four distinct representations. Analysis of the data revealed that students’ approaches to these tasks were affected by the newly explicit features present within each representation. Additionally, the ordering in which the representations were presented to the students influenced the specific features students took notice of and implemented into their approaches to the tasks. These findings can better inform instruction and future research involving chemical representations such that students will form a solid foundation in working with and pulling relevant information from various representations when solving chemistry tasks. 

Studies investigating chemistry students’ understanding of intermolecular forces have listed alternative conceptions; however, there is a call to investigate why students might have these alternative conceptions. This study describes how second semester general chemistry students predict the location of dipole–dipole forces between two molecules from a resource activation perspective. During interviews, 18 students were asked to describe the location of forces between four pairs of molecules. Students relied on one or more of the following approaches in determining location: (1) attraction between opposite charges, (2) electronegativity differences, (3) biggest electronegativity values, (4) largest atomic size, and (5) molecular shape. Each student’s approach is characterized by the resources being activated and, in particular, students’ use of electronegativity. Students’ use of electronegativity varied, including comparing electronegativity values between unbonded atoms within a molecule and between atoms present on different molecules. The findings suggest future research directions and teaching implications that could improve students’ understanding of intermolecular forces including the explicit integration and assessment of the concepts of electronegativity and intermolecular forces. 

Education in organic chemistry is highly reliant on molecular representations. Students abstract information from representations to make sense of submicroscopic interactions. This study investigates relationships between differing representations: bond-line structures, ball-and-stick, or electrostatic potential maps (EPMs), and predicting partial charges, nucleophiles, and electrophiles. The study makes use of students’ answers in hot-spot question format, where they select partially charged atoms on the image of a molecule and explanations. Analysis showed no significant difference among students when predicting a partially positive atom with each representation; however, more students with EPMs were able to correctly predict the partially negative atom. No difference was observed across representations in students predicting electrophilic character; while representations did influence students identifying nucleophilic character. The affordance of EPMs was that they cued more students to cite relative electronegativity indicating that such students were able to recognize the cause for electron rich/poor areas. This recognition is central to rationalizing mechanisms in organic chemistry. This study offers implications on incorporating EPMs during instruction and provides evidence-based support in how EPMs could be useful in promoting learning on topics that relate to an uneven charge distribution. 

The Brønsted–Lowry acid–base model is fundamental when discussing acid and base strength in organic chemistry as many of the reactions include a competing proton transfer reaction. This model requires evaluating chemical stability via a consideration of electronic granularity. The purpose of this study is to identify students’ mental models on acid and base strength in terms of granularity and stability. Fourteen students enrolled in organic chemistry participated in this case study. Data were collected through semi-structured interviews including total case comparison tasks on stability, acidity, and basicity. Analysis of data revealed that there were four groups of students differentiated by their reasoning: (1) acid and base strength through structure without association to stability, (2) acid and base strength through electronics without association to stability, (3) acid strength associated with electronically centered stability, and (4) acid and base strength associated with electronically centered stability. This characterization can support teaching and research to promote reasoning that leads to a more consistent mental model across acid and base strength.