Organic synthesis problems are a common assessment tool in organic chemistry courses, as they give instructors the opportunity to determine students’ ability to integrate and apply their knowledge of reactions and skills learned in the course. However, students often tend to be unsuccessful in solving them, even if they appear to have a strong grasp on other course material. We hypothesized that part of the reasoning behind this issue is because it can be challenging to integrate learning activities into the curriculum that give students the opportunity to apply their knowledge to synthetic problem solving, while still giving students the opportunity to master the underlying concepts (knowledge of organic reactions and reaction mechanisms). In addition, there is a gap in our understanding of the mental models students construct while solving these problems, as there is no evidence that they approach these problems in the same manner that experts do (i.e., retrosynthetic analysis). The research described in this thesis was performed to address these issues in two ways. First, we designed learning activities for students that were meant to help them develop more systematic approaches (whose benefits are supported by evidence) to solving synthesis problems, and determining if those learning activities could produce significant learning gains. The learning activities we designed were made available to students through out-of-class learning workshops, where learning gains were primarily measured through the analysis of students’ synthetic problem-solving abilities, assessed immediately before and after the workshops. Second, we sought to obtain a better understanding of students’ mental models when solving synthesis problems; specifically, we wanted to see if they had well-defined strategies for approaching these problems, and if they had a canonical understanding of how these strategies were meant to be applied. To do so, we invited students to participate in semi-structured think-aloud interviews, where participants were asked to solve synthesis problems. We investigated both of these topics using a constructivist paradigm for learning, which states that knowledge is constructed in the mind of the learner rather than passively imparted. The process of knowledge construction is heavily influenced by the prior knowledge and experiences of the learner, and meaningful understanding of new knowledge is unlikely to occur if new knowledge cannot be accommodated by existing knowledge structures. Results from these studies indicated that the workshop-style intervention did not have any effect on students’ ability to successfully solve synthesis problems, but we did observe proficiency in the ability to use expert-like strategies, suggesting that more practice over time could lead to the ability to solve synthesis problems more effectively. Our analysis of the interview data showed that some students can proficiently use strategies in situations that are familiar to them, but do not appear to be able to apply those strategies to predict outcomes in unfamiliar situations; further, we observed a strong reliance on the use of reasoning that was based on memorized rules. Future work could further explore the mental models that students construct for solving synthesis problems; we recommend the incorporation of specific instruction on the use of synthesis problem-solving strategies, and research could explore the relationship between students’ abilities, and how synthesis is taught, practiced, and assessed in the organic chemistry curriculum.

Neste trabalho o objetivo foi analisar um estudo sobre a percepção de estudantes do 2o e do 3o ano do Ensino Médio quanto à representação submicroscópica de processos de mudança de estado físico da matéria, pois, em minha carreira docente, sempre percebi grande dificuldade dos alunos nas correlações entre o universo químico macro para o submicro. Foi utilizada uma metodologia qualitativa, com a participação de 32 alunos de um colégio particular da cidade de São Paulo, SP. A sequência das atividades desenvolvidas iniciou-se pela leitura de um texto sobre propriedades da matéria, seguindo-se uma aula experimental sobre pontos de fusão e ebulição de substâncias puras e misturas. Após discussões em pequenos grupos e, subsequentemente, com uma exposição dos resultados com a sala em geral, foi proposto que os estudantes elaborassem imagens que representassem sua compreensão acerca do fenômeno de mudança de estado físico no nível submicroscópico. Após um encontro com discussões sobre as imagens produzidas nas cartolinas, elaborou-se um recurso audiovisual por grupo sobre processo de fusão e/ou ebulição. Para um entendimento mais preciso dos modelos produzidos foram feitas entrevistas com os grupos, tanto pós-produção das imagens da cartolina como também do recurso audiovisual. Foram elaboradas categorias das imagens, fornecendo indícios analíticos comparativos nas diferentes fases das atividades executadas, do que se pôde inferir que, a princípio, houve dificuldade, por parte dos estudantes, em expor seus modelos, e as explicações referentes ao domínio submicro no início do processo, além de simples, apresentavam erros conceituais, tais como a posição espacial das partículas ou a indistinção entre substância e mistura. Ao final do processo, pós-produção do recurso audiovisual, identificou-se uma evolução positiva considerável dos modelos expressos, por apresentarem características mais consistentes cientificamente, como também o discurso dos estudantes tornou-se mais coerente e seguro. Percebemos a importância de criar oportunidades frequentes para que os estudantes construam modelos sobre fenômenos, com diferentes formas de representação, sendo o processo apoiado por discussão, pois, além do fato de essa prática favorecer a percepção de suas dificuldades conceituais, isso os ajuda a selecionar e a organizar suas informações, contribuindo para que desenvolvam concepções escolares, acerca do assunto estudado, mais próximas daquelas aceitas pela comunidade científica. Também pudemos constatar que a diversidade de linguagens se faz necessária no ensino de Química, pois, para se atingir maior audiência, há a obrigatoriedade de diferentes formas de expressão do mesmo contexto, o que chamamos de multimodalidade. Concluímos que esse sistema de aprendizagem multimodal é importante, pois, com o uso de diversas formas de abordagem, por meio de diferentes ferramentas (textos, experimento, imagens, discussão), conseguimos não só alcançar maior interesse de grande parte dos estudantes, mas que eles fossem participantes ativos e críticos, fazendo parte da construção do seu conhecimento, ao invés de serem simples ouvintes que absorvem informações. / This work aims to analyze a study on the perception of students of 2nd and 3rd year of high school as the submicroscopic representation of the physical state of change processes of matter, as it was perceived in my teaching career, great difficulty of the students in the correlations between macro chemical universe for submicron one. A qualitative methodology with the participation of 32 students of a private school in São Paulo was used. The sequence of activities began by reading a text about the properties of matter, followed by an experimental class on melting points and boiling of pure substances and mixtures. After small group discussions and consequently with an exhibition of the results with the room in general, it was proposed that students draw up images that represent their understanding of the physical state change phenomenon in the submicroscopic level. After a meeting with discussions on the images produced on cards, an audio-visual resource per group on melting and / or boiling process was developed. For a more precise understanding of the models produced interviews were conducted with groups, both post-production of cardboard images as well as audio-visual resource. Images of the categories have been prepared providing comparative analytical evidence in the different phases of the activities performed, in which we can infer that the beginning was difficult for students to expose their models and explanations for the submicron domain early in the process, as well as simple, presented conceptual errors, such as the spatial position of the particles or blurring of the substance and mixing. At the end of the process, post-production of audiovisual resource has been identified a significant positive evolution of models expressed for having more consistent characteristics scientifically, as well as the speech of students has become more consistent and secure. We realize the importance of creating opportunities for students to build models of phenomena, with different forms of representation, the process being supported by discussion, because besides this practice favors the perception of their conceptual difficulties, it helps to select and organize their information, helping to develop educational concepts on the subject studied closer to those accepted by the scientific community. We can also see that the diversity of languages is necessary in the teaching of chemistry because it was realized that to reach a bigger audience there is the requirement of different forms of expression of the same context, what we call multimodality. We conclude that this multimodal learning system is important because, with the use of various forms of approach, using different tools (texts, experiment, images, discussion), we can not only achieve greater interest in many of the students, but they are active and critical participants, part of the construction of knowledge, rather than being mere listeners to absorb information.

Quality Teaching (QT) is a sought-after professional goal for educators and schools alike. It is easy to observe, harder to define, and hardest to understand how to achieve. This study attempted to identify QT amongst a select group (N = 6) of Boston-area award-winning high school chemistry teachers. Participants were selected based on having received at least two American Chemical Society-sponsored awards within the past ten years. Data were collected through survey, personal interview, classroom observations, post-observation debriefs, anecdotal information provided by teacher colleagues, supervisors, and past students, student success on externally administered chemistry examinations, and a capstone focus group interview with the teacher- participants. These data were then coded and cohered with two measures of exemplary teaching: The Massachusetts Department of Elementary & Secondary Education Educator Evaluation Rubric and the American Chemical Society Guidelines for Middle- and-High School Chemistry Teaching. Definitions for QT in general and high school chemistry teaching in particular are detailed from references in the Literature Review. Surveys and interviews were conducted via email and Zoom chats, and vii observations during COVID were conducted also by online Face-timing. Colleague, administrator, and past student anecdotes were obtained through these award-winning teachers’ award nomination letters that I had access to in my role as a member of the Northeastern Section American Chemical Society’s (NESACS) High School Awards Committee and as Chairperson for the HS Education Committee. I also had access to student results on externally administered local and national chemistry exams in my role as co-administer of the Ashdown Exam and Section Coordinator for the US National Chemistry Olympiad (USNCO). The findings of this study showed that these award-winning teachers (AWTs) took varied pathways and educational backgrounds to arrive at their profession. Participants all agreed that there is no one best way to teach, but many right ways to get to award- winning teaching. These teachers all possessed “It,” that elusive, mystical, some say innate, art of teaching born of passion, charisma, and love of working with children alongside a continual drive to improve pedagogical practices. This study identified that drive as “relentless expectations,” both for themselves as constant lifelong learners and their students for whom they set high standards. Though recognized by these awards, all of these teachers expressed humility and claimed that other colleagues were equally qualified to be award-winners. Colleagues shared that this study’s participants were “teachers’ teachers” and selfless collaborators. Supervisors related that these great teachers made great schools, and past students exclaimed that these teachers transformed students’ lives and career pathways. The data suggest that award-winning status as a secondary high school chemistry teacher must incorporate a variety of factors, including a love of science learning, a mastery of the study of chemistry with an on-going interest to forward this learning, a passion for teaching and seeing teenagers succeed in learning chemistry, the ability to create a classroom of caring and trust to allow students to take academic risks, self- motivation to collaborate with colleagues through meeting, programing, and publication, self-confidence with a strong voice, and empathy. This study identified two overlooked factors that maintain award-winning teachers: relationships and reflection (the “R & R” of AWT). Other factors that contribute to AWT include supportive school and community with resources available to both teacher and student, freedom and professional trust to be able to innovate and create curriculum, and teachers’ creation and participation in collaborative venues such as collaboration time, workshops, presentations, and conferences. Participants in this study came to chemistry teaching as a second career and state that they acquired their award-winning pedagogy through a combination of most of these factors. Though each of their voices, classrooms, and school buildings looked different, these factors in total provided a common set of criteria to produce the award- winning teaching portrayed in this study.

Organic Chemistry has been described as a challenging and confusing course for undergraduate students. Novices in the field have been struggling to understand fundamental concepts relating to organic mechanisms and organize their knowledge around surface features such as functional groups rather than deep underlying features. At the University of Ottawa, a new “Mechanistic patterns and principles” curriculum was designed and implemented, organized by the underlying mechanistic patterns that govern reactions rather than the traditional surface features approach. The redesigned curriculum emphasizes principles of reactivity in organic chemistry and is organized in a gradient of difficulty. The three studies included within this work act as part of a larger evaluation of the redesigned curriculum, specifically investigating an instrument to assess the formation of expertise in organic chemistry and an instrument to capture self-efficacy beliefs in organic chemistry as students progress throughout the curriculum. In the first two studies, an open and closed online categorization task was delivered to Organic Chemistry II students at both the beginning and end of their course. The open sort provided insights regarding how participants choose to sort, while the closed sort measured participants' ability to categorize reactions according to their underlying mechanistic pattern. In the first study, we provide an in-depth analysis of the changes in expertise that occur with respect to the expertise of their choices and ability. Findings from this work demonstrated a positive shift from students attending to surface to process-oriented features in the open sort, as well as an increase in students’ ability in the closed sort. The following-up study investigates the relationship between the expertise demonstrated by participants in the open and closed sorts. Additionally, this work compares these measures of expertise against varies other metrics, including a high-stakes categorization task, and academic performance to increase the validity, and probes at the reliability of findings. Findings from this work demonstrate a strong relationship between the expertise demonstrate in the online task and academic performance, as well as describe an evolving relationship between the expertise demonstrated in students’ choice and ability as they progress throughout the course. While previous work in the evaluation of the curriculum demonstrated that students possess greater ability, it is unknown whether this also translates to an increase in their beliefs about their abilities. The last study included within this work moves beyond cognitive outcomes of the curriculum to investigating the role of self-efficacy beliefs in the curriculum. Self-efficacy beliefs are defined as an individual’s belief in their capability to perform a specific task or objective successfully. This work intends to construct and validate a task-specific, multi-dimensional self-efficacy beliefs instrument for undergraduate students in the domain of organic chemistry. Pre-administration validity evidence, including test content and response process validity, was collected. Data for internal structure validity evidence was collected from a single administration with Organic Chemistry I students (N=78) to 7-factor structure within the final 39 item instrument. Due to the small sample size, these results are interpreted with extreme caution. Future work with this instrument aims to improve the validity evidence collected by expanding the sample size and evaluate the influence curriculum on self-efficacy beliefs, and who, based on demographic variables, may be benefiting the most from the transformed curriculum.

The aim of this study has been to examine how distance education is different from regular education, what problems arise from these differences and what strategies maya id in solving those. This should be seen in the light of a reported increase in the demand for flexible courses for educating adults and an ongoing development project. Qualitative interviews were conducted with teachers currently teaching both regular and distance courses in subjects containing chemistry. It was found that the teachers view of the differences and problems associated with distance education was; large number of drop-outs, the teacher as a guide, limitations on online communication, lack of interaction between students and uncertainties regarding the motivation of the students. As drop-out rates have been determined to chiefly depend on factors outside the control och either the school or the teacher the attention was turned toward three main areas; motivation, interactions and discussions and the role of the teacher. Previous studies have found that motivation differs for adult and youth learners, but a possible pathway is to work with building the student’s self-efficacy. Student interaction was perhaps the biggest issue seen by the teachers and there are no sure-fire ways to improve it. The suggestion offered is to have a introductory period with intense activity from the teacher, and potentially a face-to-face meeting. Although the teacher should generally stay away from any active student-discussion, a certain amount of moderation might be prudent. The interviewees felt that the role of the teacher was more that of a guide, but it should also be added that it contains elements of motivator, moderator and instigator of discussions.

Chemists use the electron-pushing formalism to rationalize, analyze, and explain how a chemical reaction occurs on an electronic level. The electron pushing formalism (EPF) is the curved arrows representing electron movement. Some research on undergraduate organic chemistry students’ understanding of the electron pushing formalism has presented evidence that some students do not find the electron-pushing formalism meaningful. Research at the University of Ottawa found that the EPF symbolism is meaningful to the participants because they interpret EPF arrows and use charges and mapping to problem-solve. At the University of Ottawa, the organic chemistry curriculum was changed in 2012 to have students learn and interpret reactions based on similar reactivity patterns. The goal of the redesign was to give students the tools to analyze, predict, and explain how reactions occur instead of memorizing. An initial section of the curriculum is dedicated to teaching the electron-pushing formalism before any reaction. An exam analysis was conducted to see the new curriculum's effect by looking at students' drawn structures and EPF arrows. Students demonstrated minimal errors when drawing the EPF arrows and scored higher on familiar and unfamiliar reactions following the new curriculum, which suggests students found the EPF arrows meaningful. The following think-aloud interview study better captured student interpretations of the EPF arrows to determine what features students found relevant and whether the students who could explain a conceptual understanding of the EPF arrows could express a deeper understanding. The think-aloud interviews found that students do place meaning into organic chemistry representations as students were thinking about how to draw the EPF arrows based on prior knowledge. The data from the two previous studies were collected near the end of the course when students had a significant amount of experience, while students’ initial interpretations of the EPF arrows are needed. The primary focus of this thesis is to understand how students initially interpret the electron-pushing formalism arrows and look further into previous findings, which include electron movement, bond-forming and breaking processes, mapping, charges, stepwise reasoning, and transplanting electrons. Twelve students were recruited from Organic Chemistry I and interviewed over three weeks after being taught the electron-pushing formalism. The interviews were conducted using a think-aloud procedure to capture students’ thoughts, and each interview lasted approximately 1 hour. The instrument consisted of six organic chemistry questions, specifically chosen, as students would not encounter them in the class and would have to interpret the representations. The transcripts were analyzed with respect to the previous studies' findings and compared among participants to explore students’ interpretations and use of the EPF arrows. The findings from this study suggest participants found the EPF arrows meaningful because participants interpreted the representations as electron-movement, bond-forming, and bond-breaking processes which contrasts some prior research that reported students do not find the EPF arrows meaningful (Bhattacharyya and Bodner, 2005; Graulich, 2015). Participants connected the EPF arrows to electron movement, bond-forming, and bond-breaking processes. Participants compared surface features to determine how to draw the EPF arrows. Participants’ visualization and how they approached the reactions differed. Participants’ visualizations of the organic chemistry reaction were divided between a stepwise or concerted visualization. Most participants approached the EPF arrows stepwise as a problem-solving tool as it was easier for them to understand. Participants correctly interpreted most bond-breaking EPF arrows, but some participants relocated the electron pair onto a different atom instead of forming a bond. Participants mainly mapped the carbon atoms with numeric labels and found implicit atom-type questions challenging. Participants interpreted charges as an important surface feature and used charges to help them solve the question. Participants viewed charges as a reactive location where bonds break and form and compared the number of charges between reactants and products to check whether their answers were correct. The results suggest the participants in the study found the EPF arrows and made meaningful connections at the submicroscopic level with minimal experience. Mastering the EPF arrows at the beginning of the course appears beneficial to student learning because participants interpreted the EPF arrows as a meaningful representation suggesting that the EPF arrows are less of a barrier when learning and mastering organic chemistry, under the University Of Ottawa’s organic chemistry curriculum as intended. Since the EPF arrows are less of a barrier, students can focus on other organic chemistry concepts and can be more successful which is seen in the first exam analysis where minimal errors were seen. The first exam analysis observed minor pentavalent atoms and errors with the EPF arrows (Flynn and Featherstone, 2017). The following interview study found students described mapping, charges, stepwise, and chemistry reasoning when discussing electron movement (Galloway et al., 2017). The findings from this work demonstrated the EPF arrows as a representation are meaningful to participants as they interpreted the EPF arrows after being recently taught. Similar findings at a different institution using a revised curriculum that focuses on the EPF at the beginning of the course found students were more likely to use the EPF arrows and were more likely to provide the correct answer than their counterparts (Crandell et al., 2018; Houchlei et al., 2021). Research at institutions adopting the functional group curriculum reported that students did not find the EPF meaningful (Bhattacharyya and Bodner, 2005; Ferguson and Bodner, 2008; Grove, Cooper, and Rush, 2012). The findings suggest that the time spent mastering the EPF arrows at the beginning of the course is beneficial when learning organic chemistry because the symbols are less likely to be a hindrance through misinterpretation, and students can focus on mastering organic chemistry concepts. Implications for teaching and learning include providing clarity on interpreting the EPF arrows and using the transplanting processes to demonstrate other chemical possibilities. Participants demonstrated comparing reactants and products when problem-solving. When students face difficulty, they should compare the products of chemical processes (bond-forming, bond-breaking, or electrons moving). The correct process has the EPF arrow starting from electrons and point to an atom or bond, maintains the conservation of atoms, and electrons stay with one of the originating atoms. The other processes will not follow one of the above principles, thus making them illogical. Future work could further explore if students interpret the EPF arrows as a whole or if they interpret the arrowhead and arrow tail. Why do some students face difficulty keeping electrons on an originating atom? Why do some students face difficulty conserving atoms, electrons, and charges throughout a reaction? Whether the findings are generalizable by expanding the sample size. In the context of the new curriculum, it appears students' have acquired a better understanding of the EPF. The results are promising because participants with minimal experience interpreted the EPF arrows and found them meaningful as a symbolic representation aligned with the curriculum's intentions.

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