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Resonance is a fundamental chemistry concept first introduced to students in General Chemistry I, reintroduced in Organic Chemistry I, and then utilized throughout other higher-level chemistry courses. A molecule or ion can be said to exhibit resonance when it can be represented by two or more chemical structures (i.e., Lewis structures) that differ only in their arrangement of electrons. In other words, resonance represents the electronic structure of a molecule or ion when a single Lewis structure does not adequately depict the true distribution of electrons. The molecule or ion is best represented as a combination of all of the structures and is called the resonance hybrid. Resonance is a tool that practicing organic chemists use to better understand the electronic structure of molecules or ions and to make predictions about molecular behavior (e.g., stability, reactivity, etc.). Therefore, because resonance is a useful tool that helps scientists understand and predict chemical phenomena, it is important for chemistry students to understand and practice using it. The current educational research shows that General Chemistry I and Organic Chemistry I students have difficulties understanding resonance. Unfortunately, little is specifically known about the possible origins of these challenges and how instruction might influence students' understandings of resonance. These challenges can potentially impact students' success in their chemistry courses, as developing a foundational understanding of resonance is essential to students' understanding of other higher-level chemistry concepts. Thus, the overarching goal of this study, which was guided by variation theory, is to investigate the teaching and learning of resonance from three different perspectives (instructor, classroom, and student perspectives) in the courses it is first introduced, General Chemistry I and Organic Chemistry I. The following three research questions (RQ) were addressed: (RQ1) What do General Chemistry I and Organic Chemistry I instructors intend for their students to understand about resonance? (RQ2) What is possible for General Chemistry I and Organic Chemistry I students to understand about resonance in General Chemistry I and Organic Chemistry I classrooms based on the information presented to them in their classes? (RQ3) What do General Chemistry I and Organic Chemistry I students understand about resonance in General Chemistry I and Organic Chemistry I classrooms after learning about it in their General Chemistry I and Organic Chemistry I classrooms? By answering these three research questions, (1) I identified eleven features of resonance that instructors believe to be critical for their students to understand about resonance (via instructor interviews), (2) I identified how/if these eleven features of resonance are made available for students to learn about in their classrooms (via classroom observations), and (3) I identified what students understand about each of the eleven features of resonance (via student interviews). These findings were then compared to draw overarching results. For example, by comparing the results from RQ1 and RQ3, I identified differences in what instructors intended for students to understand about resonance versus what students actually came to understand about resonance. Each of these comparisons is discussed in the chapters of this dissertation. Overall, I found that while instructors in this study believed a conceptual understanding of resonance was important, they tended to teach and assess students in a way that prioritized their operational understanding of resonance. For example, instead of focusing on the underlying concepts of resonance, such as the resonance hybrid, while teaching students about resonance, the instructors tended to focus on the rules and processes associated with drawing resonance structures. Consequently, many of the students in this study also tended to emphasize an operational understanding of resonance and often lacked a conceptual understanding of resonance, expressing misconceptions while discussing it. Based on the findings presented herein, recommendations are discussed to improve the teaching practices and instructional materials related to resonance, potentially resulting in more students coming to a meaningful understanding of resonance. [The dissertation citations contained here are published with the permission of ProQuest LLC. Further reproduction is prohibited without permission. Copies of dissertations may be obtained by Telephone (800) 1-800-521-0600. Web page: http://www.proquest.com/en-US/products/dissertations/individuals.shtml.]

Molecular representations that show chemical bonding are ubiquitous in general and organic chemistry. These help in communicating chemistry concepts that are fundamental to understanding "how" and "why" molecules interact. The goal of this dissertation work is to offer an evidence-based report on the affordances and limitations of the variety of molecular representations by chemistry topic. The variety of representations investigated are chemical formula, Lewis dot structure, line-angle diagram, ball and stick, space filling, and electrostatic potential maps. Five studies were conducted with general and organic chemistry students and three key findings emerged. First, affordances and limitations of molecular representations are perceived by the students - they were more likely to perceive use of textual/hybrid representations in enacting chemical conventions. Second, affordances and limitations of molecular representations depend on the intent of utility - students were more likely to utilize visual representations to make visual estimates and recall electronic features. Third, the improvements to current curriculum can benefit by using an anti-deficit framing. With these findings, themes are presented to offer broader impacts. These include, use of anti-deficit framing that focuses on improving curriculum and offering feedback via assessments, learning with representations by keeping in mind the explicit and implicit features, and accounting for students' backgrounds. A vision for how to instruct and assess with molecular representations is offered at the end. [The dissertation citations contained here are published with the permission of ProQuest LLC. Further reproduction is prohibited without permission. Copies of dissertations may be obtained by Telephone (800) 1-800-521-0600. Web page: http://www.proquest.com/en-US/products/dissertations/individuals.shtml.]

As educators, our goal is to help our students be successful, but in order to accomplish this, we need to understand what factors contribute to student success. One factor, small-group active learning, has been correlated to improved academic outcomes; however, the magnitude of this improvement can vary across different courses, different types of group work, and even across courses that use the same group work structure. Therefore, it is important to understand what aspects of group work contribute to its effectiveness. The work presented in this dissertation investigated one specific aspect: students' cognitive engagement. This was done by analyzing the discourse that occurred between students during group work. Analysis of the engagement of the group as a whole in General Chemistry suggested some misalignment between how students were expected to engage with activity worksheets and how they actually engaged. Thematic analysis was then used to identify sources of the observed misalignment. The results suggested three themes: 1) model use, where students did not use the models provided in the activity or used them in an incomplete manner; 2) unfamiliar vocabulary, where students engaged at higher modes to understand new scientific terms; and 3) molecular representations, where students struggled to move between different representations of molecules. Engagement of each individual student within the groups was also analyzed. Results showed trends in engagement related to group size, when the activities were administered during the term, and the type of question being asked during an activity. Students showed higher modes of engagement when groups were small or when students;in larger groups worked together in smaller subsets. They also showed higher modes of engagement as well as less variation in engagement during the second half of the term. In addition, questions which required students to perform calculations had higher modes of engagement than questions that were more conceptual in nature. Analysis of student group conversations also provided insight into how the activity structure can affect student learning. Using cognitive load theory and the principles of scaffolding, activity worksheets in a Physical Chemistry class were redesigned to break down complex concepts into simpler questions and thereby reduce cognitive overload. Analysis of group conversations and both student and instructor interviews indicated that the redesigned worksheets with scaffolded questions were successful in reducing student struggle and improving student understanding. [The dissertation citations contained here are published with the permission of ProQuest LLC. Further reproduction is prohibited without permission. Copies of dissertations may be obtained by Telephone (800) 1-800-521-0600. Web page: http://www.proquest.com/en-US/products/dissertations/individuals.shtml.]

Many students in secondary grade levels struggle with proportional reasoning. Calisici (2018) found that 48 percent of students were unable to solve a multiplication problem involving fractions. Furthermore, many students struggle with complex Chemistry topics due to the difficulty many students have visualizing the microscopic scale. "3D visualization media effectively improved students' critical thinking skills and scientific attitude (Astuti et al, 2020)." In another study done in Turkey, students were asked to draw static and dynamic models of an Oxygen atom. The study concludes, "Therefore, it could be suggested that generating animations as a modeling activity helps learners to improve their mental models of the atom. (Akaygun, 2016). "Thus, this study aims to address these misconceptions using a STEM Integration approach. A paper by Roehrig et al (2021) looked at creating a framework for STEM integration. The paper gave 7 key characteristics for integrating STEM: "(a) focus on real-world problems; (b) centrality of engineering; (c) context integration; (d) content integration; (e) STEM practices; (f) twenty-first century skills; and (g) informing students about STEM careers (Roehrig et al 2021)." This study examines how students understanding of proportions and atomic composition and scale develop throughout a week-long summer camp using Nanotechnology as the driving phenomena. Implications of this integrated STEM approach as well as students conceptual understanding is then examined and discussed. [The dissertation citations contained here are published with the permission of ProQuest LLC. Further reproduction is prohibited without permission. Copies of dissertations may be obtained by Telephone (800) 1-800-521-0600. Web page: http://www.proquest.com/en-US/products/dissertations/individuals.shtml.]

To deliver successful integration of virtual reality (VR) technology into chemistry education, it is essential that students have clear and positive perceptions about the purpose and the value of such integration. An important part of establishing a plan for integrating virtual reality technology into chemistry education is to explore the current perceptions, experiences, and behaviors of students towards the use of VR technology to establish an initial baseline of skills and areas in need of development. The purpose of this exploratory mixed methods study was to explore the perceptions, experiences, and behaviors of 62 middle school students in the state of Colorado towards the use of virtual reality technology in chemistry education. Quantitative and qualitative methods were used to collect data from participants using a demographic survey, observations, interviews, and a student perception survey. Participants went through a chemistry exercise delivered through a VR application called Molecule Builder. The first research question asked: "What are middle school students' perceptions toward using VR technology as a learning tool in the chemistry exercise?". For this research question, the quantitative portion of the data were collected using 24-Likert-scale items in the student perception survey completed fully by 60 student participants and partially by two participants. Quantitative results of the student perception survey yielded an overall mean of 4.58, indicating that student participants, overall, had very positive perceptions of VR as a learning tool. In addition, the qualitative findings showed the emergence of three themes through the analysis of student responses to the five open-ended questions in Section B: Reflections in the student perceptions survey: (a) advantages of VR as a tool to learn chemistry, (b) disadvantages of using VR as a tool to learn chemistry, and (c) suggestions about using virtual reality applications for teaching chemistry. The second research question asked: "Are there any differences between female and male middle school students' perceptions toward using VR technology as a learning tool in the chemistry exercise?". This research question was answered using the findings from the 24 Likert-scale items in Section A: Perceptions in the student perception survey, the demographic data from the demographic survey, and participants' responses to open-ended questions in Section B: Reflections in the student perception survey. Quantitative results of the student perception survey yielded a non-statistically significant difference between female and male students' perceptions towards utilizing VR for learning chemistry. The results revealed that female and male students have similar perceptions towards using VR as a tool to learn chemistry. In addition, the qualitative findings showed that both females and males had similar perceptions on most of the three themes and nine sub-themes in general. The third research question asked: "How do middle school students describe their experience during the chemistry exercise using the VR tool?". This research question was answered using structured interviews with all 62 participants. The majority of participants expressed an overall sense of a positive experience of the chemistry exercise using the VR tool. Two main themes were identified during the interviews: (a) positive experiences and (b) mixed experiences. The fourth research question asked: "How do middle school students behave before, during, and after using the VR tool to conduct the chemistry exercise regarding emotions, body language, and any apparent reactions?". This research question was answered using observation notes and participants' responses to three open-ended questions in section C: Behaviors in the student perception survey, which were completed by all 62 participants. The emergent themes from participant behaviors before using the VR tool to conduct the chemistry exercise were: (a) exited, (b) anxious, (c) ambivalent, and (d) joyful. The emergent themes from participant behaviors during the use of the VR tool to conduct the chemistry exercise were: (a) joyful, (b) engaged, (c) virtually present, and (d) ambivalent. The emergent themes from participant behaviors after using the VR tool to conduct the chemistry exercise were: (a) motivated, (b) joyful, (c) accomplished, (d) surprised, and (e) dissociated. In conclusion, results and findings indicated that the use of VR as a tool to learn chemistry was perceived positively by middle school students without gender differences. Additionally, the majority of students had positive experiences using the VR application to build molecules. Finally, students' behaviors were mostly positive towards the use of VR as a learning tool. The findings and recommendations made in the study could be addressed and utilized by the stakeholders including policymakers, administrators, and educators in the integration of virtual reality technology in the classroom and education in general. [The dissertation citations contained here are published with the permission of ProQuest LLC. Further reproduction is prohibited without permission. Copies of dissertations may be obtained by Telephone (800) 1-800-521-0600. Web page: http://www.proquest.com/en-US/products/dissertations/individuals.shtml.]

One of the goals of science education is to help students make sense of the world around them. To that end, it is critical that students understand the central ideas in each discipline like, in chemistry, energy and interactions. These ideas are of particular importance because they are directly related to one another and are relevant across other science disciplines. Unfortunately, researchers have found that students often struggle to develop a deep understanding of these ideas. To uncover better ways to support students' learning, I explored how students understand interactions and energy in both chemistry and biology. In this dissertation, I focused on London dispersion forces (LDFs), a type of intermolecular force (IMF) which occurs between all atoms and molecules. Specifically, I used the lens of causal mechanistic reasoning to think about students' knowledge. That is, how students connect the properties and behaviors of the underlying entities to the overall phenomenon. If we can help students to develop this type of understanding, they may be able to make powerful predictions about new, unfamiliar phenomena in which IMFs play an important role. Additionally, I explored how students thought about the energy changes which result from the formation of LDFs. Lastly, I designed assessments to elicit and characterize explanations of protein-ligand binding, a biological phenomenon governed by IMFs. To explore these questions, I used a mix of qualitative and quantitative techniques. I designed tasks to elicit causal mechanistic responses from students, using students' responses to refine the task design. I also developed coding schemes to characterize students' engagement in causal mechanistic reasoning. Furthermore, I developed and used automated resources to analyze thousands of responses in a matter of minutes. In these studies, I focused primarily on undergraduate students enrolled in Chemistry, Life, the Universe, and Everything (CLUE), a transformed, core-idea centered general chemistry curriculum. From these studies, I found that the majority of CLUE students could leverage electrostatic ideas to explain LDFs, and that a meaningful proportion of those students could provide a full causal mechanistic account. This highlights the importance of emphasizing these interactions, and the mechanism by which they form, throughout the general chemistry course sequence. Additionally, students who used causal mechanistic reasoning to discuss LDFs were more likely to use that same reasoning in the context of the associated changes in potential energy. However, this relationship was weaker among those providing a partially causal mechanistic response. This suggests that more work needs to be done to find ways of supporting students to connect the ideas of interactions and energy. Additionally, in this thesis, I describe the process by which I used iterative design to develop a task eliciting causal mechanistic explanations of a biological phenomenon. In future work, these materials can be used to explore how broader groups of students engage with this task in an effort to foster interdisciplinary coherence. [The dissertation citations contained here are published with the permission of ProQuest LLC. Further reproduction is prohibited without permission. Copies of dissertations may be obtained by Telephone (800) 1-800-521-0600. Web page: http://www.proquest.com/en-US/products/dissertations/individuals.shtml.]

The theory of evolution is the central combing theory that brings together all the tenets of biology that bring about a solid understanding of life. It is also one of the most controversial scientific theories of all time and is widely rejected by about 40% of the general public in the United States. One of the biggest reasons for low evolution acceptance is the perceived conflict between evolution and religious beliefs. Educators and researchers have been working hard to improve how we teach evolution in the classroom; some methods, such as focusing on evolution knowledge, have shown to be mixed. Sometimes it works; other times, it does not, especially with highly religious students. Other methods have shown promising, such as using culturally competent approaches when teaching highly religious students. This is where we have focused our research on reconciling religious beliefs and evolutionary theory. First, in Chapter 1, we strengthened our understanding of the theory of evolution by studying a genus of damselfly in the South Pacific. Through our molecular analyses, we described a new genus, Nikoulabasis. In Chapter 2, we studied a unique of teaching evolution to religious students. We highlighted three of the most compelling reasons students changed their minds about evolution and gave suggestions for improving evolution education in the classroom. In Chapter 3, we created and validated the predictive Factors of Evolution Acceptance and Reconciliation (pFEAR) survey tool as a way for educators to better understand what worldview factors influence students' evolution acceptance. This chapter also gives suggestions to educators on how to use the pFEAR in their classrooms. In Chapter 4, we reviewed the literature to determine the influence of popular media on students learning evolution. Evolution misconceptions come from various sources such as social interactions, religious settings, textbooks, and even teachers. But few studies looked at the influence of popular media on evolution misconceptions. In Chapter 5, we viewed and watched student mentioned evolution references and determined the accuracy with which they depicted evolution. Of the 99 references we viewed, 94% of them depicted evolution accurately. [The dissertation citations contained here are published with the permission of ProQuest LLC. Further reproduction is prohibited without permission. Copies of dissertations may be obtained by Telephone (800) 1-800-521-0600. Web page: http://www.proquest.com/en-US/products/dissertations/individuals.shtml.]

This study examined the effectiveness of three instructional and assessment strategies on conceptual understanding of the DNA molecule. Specifically, a model building task was utilized to determine if physical model construction, digital model construction with a touchscreen tablet computer, or paper worksheet activity effected conceptual understanding during the initial exposure to an abstract science concept. The DNA molecule was chosen as an exemplary three-dimensional, abstract concept with physical and digital model building interventions. Conceptual understanding was measured using an objective quiz, a drawing of a DNA molecule, and a hand-written explanation of DNA. Conceptual understanding was measured immediately after intervention and again two months later. The study examined effects to conceptual understanding of model building by comparing physical models constructed using foam pieces and digital models constructed using a touchscreen tablet computer. A control group completed a paper worksheet activity on the topic of DNA. In all conditions, an instructional video about DNA was used to standardize the content taught. To account for the potential covariates of spatial ability and attitudes to scientific inquiry, participants completed a mental rotation test to measure spatial ability and an attitudes to scientific inquiry survey.A total of 161 students across six intact 9th-grade Living Environment classrooms participated in the study. The results from the three conceptual understanding measures were compared among the three groups at both immediate and delayed post-test timepoints as well as across the two post-test timepoints. For both immediate and delayed post-test, there were no differences among the groups for the objective quiz measure. However, the physical model group outperformed the digital model and control groups in both the drawing and explanation measures at both timepoints (p < 0.01). Across the two timepoints, the control group showed a significant degree of forgetting for the objective quiz measure (p < 0.001) and the digital group demonstrated a significant degree of forgetting for the objective quiz measure (p = 0.03) and drawing measure (p < 0.001). There was a significant difference between the delayed post-test and pre-test of the objective quiz for the physical model group (p < 0.001) and no significant difference between the post-test and delayed post-test for the objective quiz for the physical model group suggesting long-term conceptual understanding and retention. Overall, the physical model group demonstrated greater conceptual understanding at immediate and delayed timepoints for the drawing and explanation measures as well as significant retention of conceptual understanding of DNA as measured by the objective quiz across three timepoints. The digital model group demonstrated a greater degree of forgetting for objective quiz and drawing measures as well as underperformed in the three conceptual understanding measures at both post-test and delayed post-test timepoints. This suggests that the greater degree of physical, haptic manipulation of a three-dimensional model aids in conceptual understanding at all three measures as well as long-term memory when compared with the limited haptic interactions with a two-dimensional touchscreen device. [The dissertation citations contained here are published with the permission of ProQuest LLC. Further reproduction is prohibited without permission. Copies of dissertations may be obtained by Telephone (800) 1-800-521-0600. Web page: http://www.proquest.com/en-US/products/dissertations/individuals.shtml.]

Chemistry students often struggle in organic chemistry courses. In fact, these courses are viewed by some as "weed-out" classes. There are many fundamental concepts covered in general chemistry that contribute to students' ability to succeed in organic chemistry. One of those fundamental topics, and the focus of this study, is the topic of acids and bases. Acid-base topics are featured in both general and organic chemistry courses, and the interests of this study lie not only within the realm of organic chemistry but also general chemistry. The purpose of this study was to determine both undergraduate general and organic chemistry students' understandings of acid-base topics. The study design was guided by the theoretical framework of phenomenography, which is focused on identifying the various ways a group experiences a given phenomenon or event. In the case of this study, the phenomenon is the topic of acid-base chemistry. Specifically, I used semi-structured interviews and activities involving molecular structures in order to determine what knowledge or information students focused on and made use of when making decisions about the identity and behaviors of acids and bases. The end goal was to obtain a set of hierarchically organized categories that represent each participant group's range of understandings of acids and bases. There were three main themes in terms of the knowledge and information that both participant groups used when making decisions about acidity and basicity: recognition, composition and structure, and behavior. In essence, participants appeared to be asking themselves certain questions when deciding if a molecule was an acid or a base: (a) "Do I know this molecule is an acid or a base?" (when relying on "recognition" of a molecule); (b) "Does this molecule look like an acid or a base?" (when focusing on the "composition and structure" of a molecule); and (c) "Does this molecule act like an acid or a base?" (when using "behavior" of a molecule to inform their decisions). When making decisions about the relative acidity of two different molecules, they appeared to be asking themselves one of an analogous set of questions: (a) "Do I know this molecule is more acidic or more basic than this other one?" (when relying on "recognition" of the molecules); (b) "Does this molecule look more acidic or more basic than this other one?" (when focusing on the "composition and structure" of the molecules); and (c) or "Does this molecule act more like an acid or more like a base than this other one?" (when using "behavior" of a molecule to inform their decisions).The data revealed that participants associated particular aspects of structure, composition, and behavior with acidity and basicity, and that many of these aspects were related to the definitions of "acid" and "base" provided by the three models of acidity (Arrhenius, Bronsted-Lowry, and Lewis). For example, participants often brought up the ability of a molecule to donate hydrogen when deciding a molecule was an acid (the Bronsted-Lowry definition of an acid) and the presence of lone pair electrons when determining that a molecule was a base (a Lewis base is defined as a species that donates an electron pair).Overall, although some participants were able to use underlying chemical principles to explain their identification of acids and bases or to choose the more acidic (basic) of a pair of molecules, most participants--at both the general chemistry and organic chemistry levels--relied on simple, surface-level features of molecules when discussing the acidity or basicity of a molecule. [The dissertation citations contained here are published with the permission of ProQuest LLC. Further reproduction is prohibited without permission. Copies of dissertations may be obtained by Telephone (800) 1-800-521-0600. Web page: http://www.proquest.com/en-US/products/dissertations/individuals.shtml.]

Density is a difficult concept for students to understand because it cannot be directly observed. If students are to gain a deeper understanding of the concept of density, they need to learn about density at both the microscopic and macroscopic levels. Virtual reality provides an opportunity for learners to experience phenomena at microscopic scales, so a density exploration simulation was created for use in a Cave Automatic Virtual Environment (CAVE). The research question for this study was: How does the 3D Density CAVE experience impact preservice elementary school teachers' understanding of the density concept at the microscopic level? Three preservice teachers were interviewed before and after their Density CAVE experience. The data collected consisted of participants' recorded audio responses, written texts, and drawings made during the interviews. Thematic analysis was used to explore the raw data. Five major conclusions can be drawn based on the evidence that emerged on participants' conceptualizations of density pre/post the Density CAVE experience: The Density CAVE experience helped participants to (a) visualize water and oil molecules and recognize there are differences in molecular structures, (b) see that molecules of water can have different spacing arrangements, (c) recognize the role of intermolecular forces in the determination of the density of water, (d) recognize that at the microscopic scale, air is not a factor in determining the density of ice. Finally, the Density CAVE experience had no impact on the participants' conceptualization of the role of molecular mass in determining density. Based on this study, students can benefit from having virtual reality experiences such as those in the CAVE to explore density at the microscopic scale. [The dissertation citations contained here are published with the permission of ProQuest LLC. Further reproduction is prohibited without permission. Copies of dissertations may be obtained by Telephone (800) 1-800-521-0600. Web page: http://www.proquest.com/en-US/products/dissertations/individuals.shtml.]

Despite the number of university students who take courses in multiple science disciplines, little is known about how they perceive common concepts from different disciplinary perspectives and to what extent they recognize connections among their courses. This dissertation explores students' perceptions of their chemistry and biology courses through the lens of two crosscutting concepts, energy and the relationship between structure, properties, and function. Energy underlies all scientific phenomena. Structure-property and structure-function relationships have long been considered important explanatory concepts in the disciplines of chemistry and biology, respectively. As such, these crosscutting concepts provide an interesting context in which to investigate student connections and misconnections across disciplines. Funded by the Association for American Universities' STEM Education Initiative, a multi-year interdisciplinary effort was underway to transform the introductory biology, chemistry, and physics courses using the lens of three-dimensional learning. To inform cross-disciplinary discussions on the improvement of undergraduate education, a series of studies using interview data were conducted. An initial set of twenty-two interviews explored a diverse group of undergraduate students' perceptions across all three dimensions (i.e. disciplinary core ideas, crosscutting concepts, and science practices). However, this resulted in a large and diverse dataset lacking sufficient depth to richly describe student experiences. This work led to three more targeted studies with a revised interview protocol focusing on the crosscutting concepts of energy and the relationship between structure, properties, and function. An additional fourteen university students concurrently enrolled in general chemistry and introductory cell and molecular biology were interviewed. Findings suggest that, while students believed energy to be important to the scientific world and to the disciplines of biology and chemistry, the extent to which it was considered central to success in their courses varied. Differences were also apparent in students' descriptions of the molecular-level mechanisms by which energy transfer occurs, revealing a disconnect between how energy is understood and used in introductory science course work. These interviews also explored students perceptions regarding (1) the meaning of structure, properties, and function, (2) the presentation of these concepts in their courses, and (3) how these concepts might be related. While the concepts of structure and properties were interpreted similarly between chemistry and biology, only three students were able to consider function productively in chemistry. Additionally, students more closely associated structure-property relationships with their chemistry courses and structure-function with biology. Despite receiving little in the way of instructional support, nine students proposed a coherent conceptual relationship, indicating that structure determines properties, which determine function, and described ways in which they connected and benefited from their understanding across both courses. The final study follows Laura, a Genomics and Molecular Genetics major, across three years of chemistry and biology coursework, including general and organic chemistry, honors cell & molecular biology, and a two-semester biochemistry course sequence. Across her four interviews, Laura consistently recognized the utility of thinking about the relationship between structure, properties, and function. However, her ability to discuss energy diminished over time. Despite describing energy to be a central and crosscutting concept in Year 1, she rarely considered it in Year 2; and, during her final interview, she noted having had a deeper conceptual understanding of energy in the past. Though some students were successful in making connections across their chemistry and biology courses, this work uncovers a need for cross-disciplinary conversations among instructors to understand the shared goals and disciplinary distinctions regarding these important concepts. [The dissertation citations contained here are published with the permission of ProQuest LLC. Further reproduction is prohibited without permission. Copies of dissertations may be obtained by Telephone (800) 1-800-521-0600. Web page: http://www.proquest.com/en-US/products/dissertations/individuals.shtml.]

Chemistry is a highly abstract discipline that is taught and learned with the aid of various models. Among the most challenging, yet a fundamental topic in general chemistry at the high school level, is molecular geometry. This study focused on developing exemplary educative curriculum materials pertaining to the topic of molecular geometry. The methodology used in this study consisted of several steps. First, a diverse set of models were analyzed to determine to what extent each model serves its purpose in teaching molecular geometry. Second, a number of high school teachers and college chemistry professors were asked to share their experiences on using models in teaching molecular geometry through an online questionnaire. Third, findings from the comparative analysis of models, teachers' experiences, literature review on models and students' misconceptions, the curriculum expectations of the Next Generation Science Standards and their emphasis on three-dimensional learning and nature of science (NOS) contributed to the development of the molecular geometry unit. Fourth, the developed unit was reviewed by fellow teachers and doctoral-level science education experts and was revised to further improve its coherence and clarity in support of teaching and learning of the molecular geometry concepts. The produced educative curriculum materials focus on the scientific practice of developing and using models as promoted in the Next Generations Science Standards (NGSS) while also addressing nature of science (NOS) goals. The educative features of the newly developed unit support teachers' pedagogical knowledge (PK) and pedagogical content knowledge (PCK). The unit includes an overview, teacher's guide, and eight detailed lesson plans with inquiry oriented modeling activities replete with models and suggestions for teachers, as well as formative and summative assessment tasks. The unit design process serves as a model for redesigning other instructional units in science disciplines in general and chemistry courses in particular. [The dissertation citations contained here are published with the permission of ProQuest LLC. Further reproduction is prohibited without permission. Copies of dissertations may be obtained by Telephone (800) 1-800-521-0600. Web page: http://www.proquest.com/en-US/products/dissertations/individuals.shtml.]

This research investigates students' learning about the electron transport chain (ETC) process in photosynthesis by watching a video followed by playing a serious board game-Electron Chute- that models the ETC process. To accomplish this goal, several learning outcomes regarding the misconceptions students' hold about photosynthesis and the ETC process in photosynthesis were defined. Middle school students need opportunities to develop cohesive models that explain the mechanistic processes of biological systems to support their learning. A six-week curriculum on photosynthesis included a one day learning activity using an ETC video and the Electron Chute game to model the ETC process. The ETC model explained how sunlight energy was converted to chemical energy (ATP) at the molecular level involving a flow of electrons. The learning outcomes and the experiences were developed based on the Indiana Academic Standards for biology and the Next Generation Science Standards (NGSS) for the life sciences. Participants were 120 eighth grade science students from an urban public school. The participants were organized into six classes based on their level of academic readiness, regular and challenge, by the school corporation. Four classes were identified as regular classes and two of them as challenge classes. Students in challenge classes had the opportunity to be challenged with more difficult content knowledge and required higher level thinking skills. The regular classes were the mainstream at school. A quasi-experimental design known as non-equivalent group design (NEGD) was used in this study. This experimental design consisted of a pretest-posttest experiment in two similar groups to begin with-the video only and video+game treatments. Intact classes were distributed into the treatments. The video only watched the ETC video and the video+game treatment watched the ETC video and played the Electron Chute game. The instrument (knowledge test) consisted of a multiple-choice section addressing general knowledge of photosynthesis and specific knowledge about ETC, and an essay section where students were asked to interpret each part of a diagram about the ETC process. Considering only the effect of treatments on score gain, regular and challenge groups reached higher scores in the posttest in comparison to the pretest after playing Electron Chute in both section of the test. However, the effect of treatments between the classes for each treatment was inconclusive. In the essay, the score gain was higher in the challenge than the regular class, but there was not a significant difference between both classes in the multiple-choice section. In regard to the learning outcomes, the initial model provided by the ETC video was mostly effective on addressing the misconception related to the oxygen production, which derives from the photolysis--or splitting--of the water molecules. Playing Electron Chute was effective on addressing most of the misconceptions targeted in the instruction design used for study. Most of these misconceptions were related to ATP and NADPH production and the cell structures where the ETC process takes place. At the end of the video+game learning treatment, a survey was used to collect data about students' experiences while playing the game. The majority of students agreed that playing the game increased their ability to explain how plants use light energy, but only about a third of them felt they could explain how ETC worked. Enjoyment and need for more explanations were different between students who attended the regular and challenge classes. The majority of the students who attended a regular class indicated they liked the ETC video and playing Electron Chute, percentage of agreement that was significantly higher than students who attended the challenge class. As a result, more students in the regular class indicated an interest in learning other science concepts like ETC. Students who attended the regular class reported that clear rules about how to play the game were helpful for learning. Further, the challenge group indicated the video and the Electron Chute game could include more explanations. These results suggest the video and game learning experience has the potential for engaging students' interest in science when they participated in a regular class. This study also demonstrates a principled approach for designing a video and game to illustrate important methods for creating content knowledge that supports students' ability to make sense of how complex systems work. Through more refinements of the game, the learning experiences could be a viable learning experience that accommodates the needs of a diverse population of students who might prefer different learning methods. [The dissertation citations contained here are published with the permission of ProQuest LLC. Further reproduction is prohibited without permission. Copies of dissertations may be obtained by Telephone (800) 1-800-521-0600. Web page: http://www.proquest.com/en-US/products/dissertations/individuals.shtml.]