Graduate teaching assistants (GTAs) play an integral role at large, research-intensive universities. GTAs have become increasingly important for instruction particularly in laboratory and discussion sections. This dissertation focuses on the use of a mixed reality teaching simulator, TeachLivE™, alongside existing Science, Technology, Engineering, and Mathematics (STEM) GTA training. In Chapter 1 we focus on an introduction to chemistry education research (CER) and the background of the study presented. In Chapter 2 the focus shifts to discussing the theoretical and conceptual frameworks as well as the relevant study instruments. In Chapter 3, we introduce the simulator as a training method for GTAs through the development of content rich concept modules. We discuss their development from selecting the relevant pedagogical skills, integrating student conceptions, and testing the modules with experienced GTAs. We found that the modules provided the GTAs a low-risk environment to practice cold calling and normalizing error skills. In Chapter 4 we analyze GTA conceptualization and use of error framing and cold calling in the simulator as well as their use of the two skills in the classroom. We found that while GTAs were able to use error framing in the simulator, they used the skill less frequently in the classroom. We found that cold calling was used frequently in the simulator and the GTAs were able to integrate the skill into their training practice and classroom. In Chapter 5 we focus on the impact of the teaching simulator on GTA instruction. We identified three GTA instructional styles and found that the method of training had an impact on the instructional styles GTAs used when they taught. Finally, in Chapter 6 we discuss the overall outcomes of the work and future works associated with the project. The result from this dissertation shows the impact of a mixed reality teaching simulator on chemistry GTAs' instructional styles and the ability of this simulator to be integrated into existing training to help prepare GTAs for their roles as instructors.

The purpose of this 3-phase transformative mixed-methods study was to use intersectionality theoretical framework to explore the science identities and relevant science learning experiences of male students of color (MSOCs) in STEM and their decisions to pursue science professions after college. Phase 1 utilized a researcher-developed survey to analyze differences in science identity scores (SIS), science relevancy scores (SRS), and decisions to pursue science professions of 702 diverse college students enrolled in STEM-related courses at a state college in Southeast United States. While there were no statistically significant differences in SIS and SRS scores regarding race/ethnicity or socioeconomic factors, statistical differences in SRS were present regarding gender. Female students had higher SRS than male students. When considering gender and socioeconomic level, a statistically significant interaction occurred across racial/ethnicity groups in SIS and SRS. Black and Hispanic males had higher SIS and SRS when at least one parent had a bachelor's degree. Phase 2 and 3 utilized interviews of five (MSOCs) from which these themes surfaced as largely shaping their decisions to pursue STEM fields: a) future-focus mindsets, b) connectedness to technology, engineering, and math, and c) science experiences and ideas. Students described the teacher's personality, the classroom environment, and the foundational characteristics of science as being critical components of relevant formal science learning experiences. Implications regarding what social justice looks like in the science classroom include1) the need to confirm SIS and SRS construct reliability from this survey instrument with a different population of diverse college students, 2) the important role science teachers and other educational stakeholders play in developing purposeful interactive instruction that adequately connects and prepares male learners for science professions, and 3) the intentional integration of real-world technology, engineering, and mathematics processes and resources in science curriculum and professional development for teachers of science.

This study investigated the extent to which elementary education mathematics methods courses exposed preservice teachers to research-based pedagogical practices grounded in cognitive science as well as best practices for mathematics instruction. A line-by-line content analysis of textbooks and course syllabi from ten teacher education programs within the State University System SUS) of Florida was completed. Evidence of the National Council of Teachers of Mathematics' (NCTM) eight high leverage Mathematics Teaching Practices (MTPs) was documented on the © Scoring Rubric for the National Council of Teachers of Mathematics' Mathematics Teaching Practices (MTPs), and Mayer's (2009) Science of Instruction Principles (SOIPs) were documented on © Scoring Rubric for Mayer's Science of Instruction Principles (SOIPs). Coding techniques were utilized to document the presence of additional theories of learning, instruction, and motivation. The results were reported using descriptive and inferential statistics, as well as relative and absolute color comparisons. Data analysis indicated that the Mathematics Teaching Practices were documented significantly more than the Science of Instruction Principles. The findings from this investigation may be used to inform textbook authors and teacher education faculty members as they develop future content for mathematics methods courses.

The purpose of this multiple comparative case study was to examine how professional development sessions based on the IQA Mathematics Toolkit rubrics influenced teachers' ambitious teaching practices, including approaches to selecting, adapting, and implementing high-cognitive demand tasks during small-group instruction in mathematics. Guided by the Instructional Quality Assessment (IQA) and the Mathematical Task Framework (MTF), this qualitative inquiry gathered data through informal interviews; participant portfolios of tasks, rubric scores, and student work samples; observation tools; and transcripts during weekly professional development sessions from two in-service elementary school teachers at a K-8 charter school in Florida. Two research questions drove this study: (a) What factors influence the selection, adaptation, and implementation of high-quality mathematical tasks for small-group instruction; and (b) In what ways are teachers' approaches to planning and implementing instruction impacted by using the IQA rubrics? Qualitative analysis of the data revealed five themes pertaining to the experiences of participants: (a) pressures from pandemic concerns; (b) perceptions of students' ability and motivation; (c) understanding of state standards and school prescriptions; (d) teachers' level of interest and exposure to outside distractions; and (e) level of experience. Teachers' approaches to high-quality tasks when mixed with heterogeneous grouping were found to best support opportunities for teacher change and provide students with opportunities to make sense of mathematics. Results show reflection of practice using the IQA rubrics can influence teachers' approaches to planning, adaptation, and implementation of tasks and support changes in classroom practice. Discussion of the findings in relation to the relevant literature, their implications, and recommendations for further research are provided. These findings add to the research in the field of mathematics education in equitable grouping strategies for small-group instruction, approaches to high-quality tasks to promote sense making in small groups and assessing ambitious teaching practices in mathematics.

The focus of this research was to expand on existing literature by providing information on elementary school pre-service teachers' ability to contextualize fraction expressions and decontextualize fraction word problems. The elementary school pre-service teachers who participated in this study were enrolled in a mathematics for elementary school teachers content course in a college of education at a large university during the Spring 2016 semester. In this mixed-method study, the participants were given the Contextualization and Decontextualization of Fractions Instrument (CDFI) which assessed elementary school pre-service teachers' ability to solve fraction word problems and identify decontextualized fraction word problems into expressions and contextualized fraction expressions into word problems. The elementary school pre-service teachers were given the CDFI before and after they completed a unit on fractions. Of the 52 participants who completed both the pre- and post- CDFI, 11 were selected to participant in think aloud interviews in which they decontextualized fraction expressions from word problems and solved and contextualized fraction word problems from expressions. Quantitative results showed an overall statistically significant difference in the elementary school pre-service teachers' pre- and post- test scores. With the exception of two questions, all questions on the CDFI showed a statistically significant difference between the pre- and the post- test scores. No statistical significance was found in the responses to the question that required the elementary school pre-service teachers to identify the expression that matched the given fraction subtraction word problem. A large number of participants correctly identified the correct subtraction expression on the pre-test, and only slightly more of them were able to identify the correct subtraction expression on the post-test. No statistical significance was found in the responses to the question that required the elementary school pre-service teachers to explain their selection of a contextualized fraction multiplication expression. Though there was an increase in the elementary school pre-service teachers' ability to explain their selection of the contextualized fraction multiplication expression, it was not statistically significant. The qualitative analysis of the think aloud interview data showed that some of the elementary school pre-service teachers struggled with contextualizing fraction expressions. Most of the elementary school pre-service teachers did not struggle with solving the fraction word problems, but did struggle with decontextualizing fraction multiplication word problems.

The undergraduate microbiology lab serves an important role in establishing a foundation of best practices in aseptic technique and infection control for pre-medical, pre-nursing, pre-pharmacy, or pre-allied health students. The high incidence of hospital-acquired infections (HAIs) in the US and evidence in the literature of less effective implementation of proper aseptic technique among apprentice doctors and nursing students suggests that more effective transfer of learning could improve implementation of these procedures in the clinical setting. The research described in this study aimed to assess learning transfer as it applied to aseptic techniques and infection control skills learned in the undergraduate microbiology lab from pre- and post-lab formative assessments to midterm and lab practical summative assessments. Assisting students in building connections between the aseptic techniques learned in general microbiology and their application in the clinical setting through pre-lab formative assessments and reflective practices may lead to improvements in use of aseptic techniques and infection control measures as they progress into clinical careers and may ultimately reduce infection rates and mortality rates due to HAIs. The first major aim of this study was to explore the experiences of students with respect to learning transfer through qualitative analysis of student responses to post-lab free-response questions regarding difficulties faced in the lab and the relevance of microbiology to students' future careers. The second major aim of this study was to determine if the implementation of an in-class pre-lab formative assessment facilitates learning transfer as evidenced by significant improvements on summative lab midterm and final lab practical exam scores. Qualitative analysis of student responses to open-ended reflection questions indicated evidence of predominantly low-road transfer with respect to transfer of automaticity. Additionally, qualitative analysis of student responses indicated evidence of lateral transfer regarding transfer of complexity. Finally, there was evidence of an evolution from near to far transfer of context indicating that students were able to perceive the application of the knowledge gained in the microbiology lab in contexts similar to the lab as well as contexts outside of the lab. Evidence from student responses suggested that primarily students intending to pursue careers in healthcare fields were able to perceive specific applications of the microbiology lab to their future careers. Further, evidence from student responses suggested that students predominantly had difficulties with procedures, interpretation of results, manual dexterity with microbiological equipment and materials, and expressed the need to practice these procedures and techniques. Statistical analyses provided quantifiable evidence that the implementation of pre-lab quizzes had both a statistically significantly positive impact and a practically positive impact on lab practical final scores in both of the semesters studied as compared to historical control groups with a large effect size. The statistically and practically significant impact of the pre-lab quizzes on lab practical final exams is an important finding and will add to the current literature on the importance of formative assessment in undergraduate microbiology education.