Thesis (Ph. D.)--Ohio State University, 2006. / Title from first page of PDF file. Includes bibliographical references (p. 119-139).

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An understanding of the level of both genetic and morphological diversity within a taxon and how that diversity is structured within and across habitats is important when determining the conservation value of that taxon and for successful habitat management programs to be developed. Atlin Lake is a large lake in northern British Columbia and is one of the largest lakes that contain relatively unperturbed populations of lake trout (Salvelinus namaycush). As the top aquatic predator, lake trout in Atlin Lake are a key component of the lake’s fish community and are important for local fisheries. I assayed lake trout from Atlin Lake and other western lake trout populations at eight microsatellite DNA loci and for body morphology to determine: (i) the level of genetic variation present, (ii) the level of substructure that occurs in Atlin Lake, and (iii) whether there was a relationship between the genetic and morphological variation present. STRUCTURE analysis identified five subpopulations within Atlin Lake. Morphological analysis was used to differentiate between the samples collected throughout Atlin Lake. Cluster analysis of size corrected data separated the fish into two groups making Atlin Lake the smallest lake identified to date to possess more than one morphotype. Genetic and morphological groupings were found not to be correlated with each other. Finally, I was interested in whether each of the genetic subpopulations contributed equally to the local fisheries catches. A mixed stock analysis of samples collected from the commercial fishery and recreational anglers indicated that all of the genetic subpopulations contribute to the fishery along with lake trout subpopulations in the interconnecting Tagish Lake; suggesting that no one subpopulation is being depleted by the fisheries. Continued genetic monitoring, however, is necessary to see if the trends in fishery contribution are temporally stable. Future studies should focus on understanding the source of the morphological variation and maintenance of genetic substructure.

Previous studies have attempted to establish an empirical link between teachers beliefs and practices. However, weak theoretical framing and ambiguity in the measurement of beliefs and practices have contributed to challenges in researching the relationship between teachers beliefs and practices, resulting in uncertainty in the prevalence of different beliefs, the amount of individual variance in beliefs, and how beliefs influence teachers classroom practices. The current study proposes a theoretical framework based on the extant literature and uses a person-oriented approach to examine early childhood teachers content-related beliefs regarding the skills necessary for school readiness. Teachers belief profiles are used to explore the link between teachers beliefs and their use of instructional time and other observed classroom practices. The influences of contextual considerations such as teacher background, classroom composition, school setting, and regional contexts on both teachers belief profiles and their classroom practices were investigated. The study found no evidence that teachers belief profiles were associated with their practices, but results suggest that contextual considerations may be more important and relevant to teachers classroom practices than previously recognized. The findings are discussed in light of previous studies and evidence regarding child behaviors that are predictive of school success. Implications for teacher education and professional development are described, as well as the need for further investigation of teachers professional contexts and the potential benefits of qualitative or mixed-methods approaches.

Self-regulation is increasingly recognized as a key component of early school readiness. Self-regulatory skills, like paying attention, ignoring distractions, following directions, and persisting on difficult tasks, are particularly relevant for school success. However, little is known about the related developmental processes that may facilitate young childrens self-regulation growth. Socio-cultural theory posits a link between childrens early language skills and their self-regulation, whereby language serves as a metacognitive tool that children use to regulate their behavior, but thus far, only limited empirical evidence supports this connection. This study explored the relationship between childrens initial language skills, self-regulation gains, and learning behaviors in pre-kindergarten classrooms. Using an array of assessment tools (including standardized language assessments, direct child measures of self-regulation, teacher ratings of language and self-regulation, and child observational data), this study employed a unique cross-validation approach to answer three main questions. The first question examined the relationship between childrens language skills at pre-kindergarten entry and their self-regulation growth during the year. The second question explored whether childrens entering language skills were associated with the learning behaviors in which they engaged in their classrooms. The final question tested whether childrens learning behaviors in the classroom mediated the relationship between their entering language skills and their self-regulation gains. The studys results demonstrated that childrens entering language skills were positively related to their self-regulation growth over the course of the pre-kindergarten year. Further, childrens entering language skills were related to classroom behaviors believed to be particularly relevant for self-regulation growth, including social and sequential learning activities. In addition, childrens language skills were positively related to involvement during learning activities, and negatively related to off-task behavior. Finally, although the overall results of the analyses did not support mediation, the models for involvement and off-task behavior approached the statistical criteria for mediation. The results suggest that early language skills may play an important role in the development of self-regulation, in part because they are an important aspect of childrens ability to become highly engaged in classroom activities.

This project focuses on whether participation in authentic research experiences has an impact on teachers understanding of the Nature of Science (NOS) and, consequently, their classroom instruction related to NOS. In my dissertation, I first explore to what extent participation in research affected teachers understanding and in what ways. I then describe any patterns that were evident in aspects of or activities within teachers research experiences that suggested that they may help make certain aspects of NOS more salient to participants. Finally, I explain the extent to which any changes took place in teachers classroom instruction that reflected shifts in their NOS understanding. Results indicate that, while participation in certain research activities may, in fact, make certain aspects of NOS more understandable for teachers, this does not necessitate change in classroom practice. Implications for research-based teacher professional development programs are explored based on these results.

The goal of this study is to investigate how a learning-progression-centered assessment system mediated the collaborative efforts between teachers and researchers in reorienting assessment toward improving the quality of instruction and supporting student learning. In particular, this study aims to understand how the learning-progression-centered assessment system can support teachers to orchestrate productive classroom discussion based on the path outlined in the learning progression to make conceptual progress. The analysis of four case teachers provides evidence that the assessment system supported teachers in developing understandings of the big ideas of data, chance and statistics and of the learning progressions of statistical reasoning. In addition, the assessment system supported the teachers in transforming assessment practices in their classrooms. The teachers demonstrated construct-centered orchestration of assessment talk: structuring classroom interaction centered on important mathematical ideas represented in the classification system and/or aligning the instructional trajectory with the learning progressions to support student learning. This study suggests that learning progressions as a classification system can be an effective tool to disrupt the historically developed classificatory system for assessment in modern schooling (i.e., right or wrong) and eventually overwrite it with a disciplinary perspective on mathematics. The field needs to develop more content-specific classification systems to inspect qualities of students reasoning and teachers interpretations of students reasoning.

This thesis applies arguments for greater diversity, and more specifically, racial diversity, on the judiciary to administrative tribunals with an adjudicative function. I draw from both formal arguments, such as institutional legitimacy, and substantive arguments, such as the different perspectives that diversity would provide, to propose an integrative conception of diversity. By relying upon concepts such as structural impartiality, I argue that an integrative conception of diversity more fully reveals the transformative potential of diversity in legal decision-making. This integrative conception is particularly well-suited to the administrative context because it demonstrates how diversity will enhance the values of participation and justification, which are instrumental to the principle of fairness. Through interviews with adjudicators and legal clinic lawyers, I offer a preliminary view of the potential impact that diverse administrative adjudicators could have in practice. Finally, this thesis offers recommendations on how this potential could be further realized.

This thesis applies arguments for greater diversity, and more specifically, racial diversity, on the judiciary to administrative tribunals with an adjudicative function. I draw from both formal arguments, such as institutional legitimacy, and substantive arguments, such as the different perspectives that diversity would provide, to propose an integrative conception of diversity. By relying upon concepts such as structural impartiality, I argue that an integrative conception of diversity more fully reveals the transformative potential of diversity in legal decision-making. This integrative conception is particularly well-suited to the administrative context because it demonstrates how diversity will enhance the values of participation and justification, which are instrumental to the principle of fairness. Through interviews with adjudicators and legal clinic lawyers, I offer a preliminary view of the potential impact that diverse administrative adjudicators could have in practice. Finally, this thesis offers recommendations on how this potential could be further realized.

Science education is increasingly organized around engaging students in scientific practices, positioning them as makers of knowledge. However, there is significant uncertainty both about how to initiate students into these practices and how domain knowledge and participation in practice should be integrated in instruction. This three-paper dissertation addresses these challenges by situating students activity within the overarching enterprise of modeling. The first paper is a conceptual review of the literature on scientific argumentation. It conceptualizes argumentation as the social activity that problematizes and stabilizes modeling practice and proposes three directions for research: carefully designing uncertainty into students activity, describing how students critique not just what they know but the means by which they know it, and attending to the development of practice. The second and third papers are empirical studies of third grade students scientific activity in a backyard ecosystem; they trace the relation between students modeling practice and the development of ecological understanding. The second paper documents four phases of instruction during one school year, following the development of one disciplinary idea, the reproductive success of plants. It traces how students activity facilitated the visibility and utility of meanings for reproduction, which, in turn, shaped students subsequent modeling practice. The third paper presents a close analysis of students work around one experiment, with which they sought to understand how different amounts of light might account for the pattern of plant distribution in the backyard. It describes the aspects of modeling practice students engaged in as they worked with the experiment, how their practice made contact with ecological ideas, and how forms of practice and disciplinary understandings developed over the course of eight weeks of activity. As a set, the papers illustrate productive contacts between the social, conceptual, and epistemic aspects of scientific activity that can be cultivated in instructional experiences that are typical in elementary school. In addition, they present, test, and refine design principles for engineering learning environments in which knowledge-making is both accessible to students and a useful foundation for disciplinary understandings.