The purpose of this study was to assess the measures of the Science Laboratory Environment Inventory (SLEI), an existing classroom environment measurement instrument, to provide up-to-date norms and validation evidence for a U.S. secondary school population. This instrument’s measures were established as a means of examining students’ perceptions of their learning environment in science classrooms, and subsequently providing indicators of performance. Pedagogical changes have taken place in the science classroom fostered by the National Science Standards. This study included an examination of the SLEI measures using Mesick’s validity framework including an in-depth analysis of the instrument’s content, substance, structure, generalizability and external validity. Rasch measurement theory was employed to investigate specific components of the instrument including item fit, rating scale function, dimensionality and individual performance information. Three hundred and fifty five high school science students completed the SLEI. Structural equation modeling was used to assess the dimensional structure of the measures of the instrument. Analyses revealed that a multi-dimensional model encompassing five distinct factors and excluding negatively worded items best characterized the SLEI measures. Multidimensional measures created by scaling the data to the Multidimensional Random Coefficients Multinomial Logit (Rasch) Model exhibited suitable rating scale structure, item quality, and reliability of separation. Analyses by academic grouping revealed that students in high achieving courses had a more favorable perception of all aspects of their learning environments when compared to students in the regular courses. In addition, student perceptions of the lab were influenced by the extent of students’ experience learning science. To determine whether differences observed by grade level could be attributable to biology learning experience versus experience in school, additional analyses were completed. The analysis revealed that differences in perception were consistent across academic achievement groups as well as experience level by first year and beyond (course level) rather than by grade level. This validation study has provided additional and up-to-date evidence concerning the validity of SLEI measures. Coupled with the existing research revealing positive correlations between student perceptions of their learning environments and their academic achievement, the outcomes reported here provide a foundation for future assessment of the relationship between classroom environment and student achievement. / Ph. D.

Efforts to improve science education have resulted in proposed innovative teaching methods and changing course sequences such as the inquiry-based Physics First curriculum. This study examined student and alumni perceptions of a Physics First course in a modified curriculum that inverted the traditional course sequence of Biology-Chemistry-Physics (BCP) to an inquiry-based Physics First (PF) curriculum in which students take an inquiry-based physics course as freshman and chemistry as sophomores. This study explored the experiences of students in their ninth grade physics course and how the Physics First curriculum influenced students’ and alumni future STEM course choices and experiences. The qualitative study included a sampling of 16 male students and alumni selected from students currently enrolled and alumni who graduated within five years of the study. All the students interviewed recalled positive, memorable experiences in their Physics-9 course as they explained in their interviews that they enjoyed their Physics-9 course and remembered details about the engaging, hands-on projects as their favorite activities. Since the adoption of the PF curriculum more students were taking honors and AP science courses and over 90% of the students at the site enrolled in four years of science even though only three years were required. Almost all of the students liked science for the first time because of the Physics-9 course.

The objective of this study is to examine the impact of students accessing Algebra 1 in the 8th grade on their science course-taking patterns in high school in a large district in the Mid Atlantic of the United States. This is an important question because many studies have shown that Algebra 1 is a "gatekeeper" course (Adelman, 1999, 2006) but there has not been much research around the impact of who has taken Algebra 1 by 8th grade and what science courses they took as a result of having access to that particular course (Xin Ma, 2009). The data will be supplied by the school district of the last two cohorts of graduating seniors who were in the district from the seventh grade on, so the analysis can be conducted on those who were subject to the same opportunities and policies. The demographic information that will be requested are: Free/Reduced Meal students (FRMS) as a proxy for socio-economic status (SES), gender, race, English as a Second Language (ESOL) level, Special Education (SPED), what grade the students took Algebra, and the science classes they took while they were in high school. The research questions will be analyzed using JMP, a statistics program supplied by Virginia Tech to see if there are any significant differences in which groups of students took Algebra 1 by 8th grade and what kinds of science courses they took. The major findings were that more White and Asian students, and higher SES students accessed Algebra 1 by 8th grade and were enrolled in more rigorous science classes in their high school career than their Black, Hispanic, low SES, Special Education or English Language peers. The results of this study could inform large school districts about the impact of Algebra 1 by 8th grade on students' science course-taking patterns and promote conversations about their policies they create about access to critical courses. / Doctor of Education / The objective of this study is to examine the impact of students accessing Algebra 1 in the 8th grade on their science course-taking patterns in high school in a large district in the Mid Atlantic of the United States. This is an important question because many studies have shown that Algebra 1 is a "gatekeeper" course (Adelman, 1999, 2006) but there has not been much research around the impact of who has taken Algebra 1 by 8th grade and what science courses they took as a result of having access to that particular course (Xin Ma, 2009). The major findings were that more White and Asian students, and higher SES students accessed Algebra 1 by 8th grade and were also enrolled in more rigorous science classes in their high school career than their Black, Hispanic, low SES, Special Education or English Language peers. The results of this study could inform large school districts about the impact of Algebra 1 by 8th grade on students' science course-taking patterns and promote conversations about their policies they create about access to critical courses. The research could be used by school leaders as context for when they examine the participation of students in their upper level science classes. It could also be used by school counselors to better communicate with families about the importance of mathematics preparation and readiness and the impact of those on other college track courses.

Kinetic studies determining the second order rate constants for the monoepoxidation of cyclic dienes, 1,3-cyclohexadiene and 1,3-cyclooctadiene, and the epoxidation of cis-/trans-2-hexenes by dimethyldioxirane (DMDO) were carried out using UV methodology. Consistent with published results, the kinetics of cis-/trans-2-hexenes by DMDO showed greater reactivity of the cis-isomer compared to that of the trans-compound. Molecular modeling studies for the epoxidation of a series of cis-/trans-alkenes, by DMDO were carried out using the DFT approach. The mechanism of epoxidation by DMDO was modeled by determining the transition state geometry and calculating the electronic activation energies and relative reactivities. The calculations were consistent with a concerted, electrophilic, exothermic process with a spiro-transition state for all cases. Kinetic studies for the monoepoxidation of the cyclic dienes showed a greater reactivity for 1,3-cyclohexadiene compared to that for 1,3-cyclooctadiene. The DFT method was employed to successfully model the transition state for the monoepoxidation of the cyclic dienes by DMDO and successfully predict the relative reactivities. Student misconceptions, at the high school and/or middle school level involving energy changes and chemical reactions have been prevalently noted in literature (by ACS and AAAS). Two examples of these misconceptions are: 1) heat is always needed to initiate a chemical reaction and 2) all chemical reactions create or destroy energy. In order to address these types of misconceptions, an educational module detailing the influence of energy changes on chemical reactions has been developed in conjunction with the Bio-bus program for middle and high school students. Visual aids and hands-on activities were developed in the module to potentially help students overcome/deal with the common misconceptions. Surveys were designed to access the situations (determine the extent of the misconceptions) and the effectiveness of the educational module, before and immediately after the module and one-month later to determine retention. The educational module has been presented to approximately 100 high school students from underrepresented communities. Pre-survey data confirmed the presence of the common misconceptions reported in the literature. Data from the post-survey indicated the new instructional module enhanced the student’s interest of science and expanded their content knowledge and laboratory skills. The post-survey data (immediately following the module) showed a significant difference in two out of five misconceptions when compared to the pre-survey data. However, this significance decreased when the 1-month post-survey data were compared to the pre-survey data.

The objective of this research is to explore the perceptions of UCF Upward Bound Program participants using focus groups and pre-posttest surveys in order to assess students' level of understanding of Science, Technology, Engineering, and Mathematics (STEM) related coursework, secondary education preparation in science and mathematics, and their perceptions of barriers to a STEM college education. Also, this study centers on the summer 2010 science and mathematics residential portion of the Upward Bound Program. Program outcomes and effectiveness were evaluated based on the change in student insight of the Upward Bound Program's stake in their secondary education. In addition, pre-posttest measures and interviews allowed a greater understanding of teacher and parent involvement in high school coursework success. Factors that involve self-efficacy, same or other group orientation and perceptions of student college environment were also analyzed. This research facilitated the understanding of first generation, low income and multicultural student's perceptions and what they view as a benefit or a hindrance to entering and successfully completing degrees in post-secondary institutions, specifically in STEM-related disciplines.

With the proliferation of 21st century educational technologies, science teaching and learning with digitally acclimatized learners in secondary science education can be realized through an online Science-Technology-Society-Environment (STSE)-based issues approach. STSE-based programs can be interpreted as the exploration of socially-embedded initiatives in science (e.g., use of genetically modified foods) to promote the development of critical cognitive processes and to empower learners with responsible decision-making skills. This dissertation presents a case study examining the online environment of a grade 11 physics class in an all-girls’ school, and the outcomes from those online discursive opportunities with STSE materials. The limited in-class discussion opportunities are often perceived as low-quality discussions in traditional classrooms because they originate from an inadequate introduction and facilitation of socially relevant issues in science programs. Hence, this research suggests that the science curriculum should be inclusive of STSE-based issue discussions. This study also examines the nature of students’ online discourse and, their perceived benefits and challenges of learning about STSE-based issues through an online environment. Analysis of interviews, offline classroom events and online threaded discussion transcripts draws from the theoretical foundations of critical reflective thinking delineated in the Practical Inquiry (P.I.) Model. The PI model of Cognitive Presence is situated within the Community of Inquiry framework,encompassing two other core elements, Teacher Presence and Social Presence. In studying Cognitive Presence, the online STSE-based discourses were examined according to the four phases of the P.I. Model. The online discussions were measured at macro-levels to reveal patterns in student STSE-based discussions and content analysis of threaded discussions. These analyses indicated that 87% of the students participated in higher quality STSE-based discussions via an online forum as compared to in-class. The micro-level analysis revealed students to attain higher cognitive interactions with STSE issues. Sixteen percent of the students’ threaded postings were identified in the Resolution Phase 4 when the teacher intervened with a focused teaching strategy. This research provides a significant theoretical and pedagogical contribution to blended approach to STSE-based secondary science education. It presents a framework for teachers to facilitate students’ online discussions and to support learners in exploring STSE-based topics.

With the proliferation of 21st century educational technologies, science teaching and learning with digitally acclimatized learners in secondary science education can be realized through an online Science-Technology-Society-Environment (STSE)-based issues approach. STSE-based programs can be interpreted as the exploration of socially-embedded initiatives in science (e.g., use of genetically modified foods) to promote the development of critical cognitive processes and to empower learners with responsible decision-making skills. This dissertation presents a case study examining the online environment of a grade 11 physics class in an all-girls’ school, and the outcomes from those online discursive opportunities with STSE materials. The limited in-class discussion opportunities are often perceived as low-quality discussions in traditional classrooms because they originate from an inadequate introduction and facilitation of socially relevant issues in science programs. Hence, this research suggests that the science curriculum should be inclusive of STSE-based issue discussions. This study also examines the nature of students’ online discourse and, their perceived benefits and challenges of learning about STSE-based issues through an online environment. Analysis of interviews, offline classroom events and online threaded discussion transcripts draws from the theoretical foundations of critical reflective thinking delineated in the Practical Inquiry (P.I.) Model. The PI model of Cognitive Presence is situated within the Community of Inquiry framework,encompassing two other core elements, Teacher Presence and Social Presence. In studying Cognitive Presence, the online STSE-based discourses were examined according to the four phases of the P.I. Model. The online discussions were measured at macro-levels to reveal patterns in student STSE-based discussions and content analysis of threaded discussions. These analyses indicated that 87% of the students participated in higher quality STSE-based discussions via an online forum as compared to in-class. The micro-level analysis revealed students to attain higher cognitive interactions with STSE issues. Sixteen percent of the students’ threaded postings were identified in the Resolution Phase 4 when the teacher intervened with a focused teaching strategy. This research provides a significant theoretical and pedagogical contribution to blended approach to STSE-based secondary science education. It presents a framework for teachers to facilitate students’ online discussions and to support learners in exploring STSE-based topics.