While there has been much discussion of cognitive processes underlying effective scientific teaching, less is known about the response nature of assessments targeting processes of scientific reasoning specific to biology content. This study used multiple-choice (m-c) and short-answer essay student responses to evaluate progress in high-order reasoning skills. In a pilot investigation of student responses on a non-content-based test of scientific thinking, it was found that some students showed a pre-post gain on the m-c test version while showing no gain on a short-answer essay version of the same questions. This result led to a subsequent research project focused on differences between alternate versions of tests of scientific reasoning. Using m-c and written responses from biology tests targeted toward the skills of (1) reasoning with a model and (2) designing controlled experiments, test score frequencies, factor analysis, and regression models were analyzed to explore test format differences. Understanding the format differences in tests is important for the development of practical ways to identify student gains in scientific reasoning. The overall results suggested test format differences. Factor analysis revealed three interpretable factors—m-c format, genetics content, and model-based reasoning. Frequency distributions on the m-c and open explanation portions of the hybrid items revealed that many students answered the m-c portion of an item correctly but gave inadequate explanations. In other instances students answered the m-c portion incorrectly yet demonstrated sufficient explanation or answered the m-c correctly and also provided poor explanations. When trying to fit test score predictors for non-associated student measures—VSAT, MSAT, high school grade point average, or final course grade—the test scores accounted for close to zero percent of the variance. Overall, these results point to the importance of using multiple methods of testing and of further research and development in the area of assessment of scientific reasoning.

Data collected in this study indicated significantly greater pre-to-post test score gains, confidence level gains, and increased student engagement in learning about electric circuits through model-based instruction compared to students who learned through more traditional teaching methods. Since the teachers in the model-based group were known to widely utilize guided whole-class discussions to foster the students' construction of explanatory models, it was deemed important to study the specific types of teaching strategies that may be supporting these positive effects. An in-depth analysis was conducted to identify teaching strategies used during whole class discussions by the two teachers whose students had the largest pre-to-post test gains. A new diagrammatic system for representing the parallel use of several nested levels of teaching strategies and their interaction with student reasoning moves was developed to support these microanalyses. This study found evidence that, in addition to previously documented dialogical strategies that teachers utilize to engage students in effectively communicating their scientific ideas in class, there is a second level of more cognitively focused model-construction-supporting strategies that teachers use to foster students' reasoning about the construction of explanatory models of scientific concepts. A compendium was developed of thirty nine whole-class discussion-based teaching strategies, each of which contributes to one of four phases (Observation, Model Generation, Model Evaluation and Model Modification) of a model construction cycle. While the thirty nine strategies were identified within the teaching of high school electric circuits, it is believed that they are general enough to apply to other topics and levels of instruction. It was discovered that even though considerable differences were observed between two model-based teachers in the ratios of student and teacher contributions to the model construction process taking place during whole-class discussions, both teachers were able to support high levels of student participation in these conversations as well as virtually identical pre-to-post test gains in circuit problem solving outcomes. This result suggests that there is not "one best way" to facilitate model-based learning. The study attempts to contribute to a coherent model of how teachers can support students' conceptual change processes through a process of scaffolding whole-class discussions.

There is a growing consensus among educational researchers that traditional problem-based assessments are not effective tools for diagnosing a student's knowledge state and for guiding pedagogical intervention, and that new tools grounded in the results of cognitive science research are needed. The ConMap (“Conceptual Mapping”) project, described in this dissertation, proposed and investigated some novel methods for assessing the conceptual knowledge structure of physics students. A set of brief computer-administered tasks for eliciting students' conceptual associations was designed. The basic approach of the tasks was to elicit spontaneous term associations from subjects by presenting them with a prompt term, or problem, or topic area, and having them type a set of response terms. Each response was recorded along with the time spent thinking of and typing it. Several studies were conducted in which data was collected on introductory physics students' performance on the tasks. A detailed statistical description of the data was compiled. Phenomenological characterization of the data (description and statistical summary of observed patterns) provided insight into the way students respond to the tasks, and discovered some notable features to guide modeling efforts. Possible correlations were investigated, some among different aspects of the ConMap data, others between aspects of the data and students' in-course exam scores. Several correlations were found which suggest that the ConMap tasks can successfully reveal information about students' knowledge structuring and level of expertise. Similarity was observed between data from one of the tasks and results from a traditional concept map task. Two rudimentary quantitative models for the temporal aspects of student performance on one of the tasks were constructed, one based on random probability distributions and the other on a detailed deterministic representation of conceptual knowledge structure. Both models were reasonably successful at approximating the statistical behavior of a typical student's data.

An initial test of scientific inquiry skills revealed that students enrolled in a computer enhanced introductory college chemistry class using a guided discovery approach produced significantly larger gains after class instruction compared with two other introductory chemistry classes at the same institution and three introductory science classes at two other college institutions. The purpose of this study was to analyze the instructional strategy in this class to understand how it may have contributed to gains in inquiry skills. Classroom observations of the computer enhanced guided discovery class and two other lecture based chemistry classes, uncovered a pattern of instruction in the guided discovery case that was markedly different from the other two classes, yet more similar to model construction processes of scientists. The central pattern of instruction in the primary case was referred to as the guided discovery approach and was characterized by instructional strategies designed to trigger generate, evaluate, and modify or GEM cycles, other teacher guidance strategies, and the integration of an interactive computer tool. Analysis of classroom observation data and student surveys confirmed a higher frequency of students' generating ideas about chemistry, constructing explanations, and quantitative problem solving in the guided discovery case than the lecture-based classes and a higher rate of teacher requests for students to engage in several of these processes. Small group observations revealed students' reasoning processes as they interacted with their teacher and the computer during instruction. Overall, compared with more traditional forms of chemistry instruction, the evidence suggests that the instructional strategies in the guided discovery case were successful in sustaining student engagement with several fundamental processes of scientific inquiry and may have led to the development of important inquiry skills. The guided discovery case used classroom activities that included finding trends, evaluating extreme cases, using incremental values, making comparisons, asking why, providing discrepant information, designing new tests, working back from the data, and thinking of an individual molecule, as several different strategies to foster inquiry. Rich descriptions of such instructional strategies may offer prescriptive methods for teachers to foster these processes in their classrooms and may represent a promising model for inquiry based instruction.

Student activity in online homework was obtained from courses in physics in 2003 and 2005. This data was analyzed through a variety of methods, including principal component analysis, Pearson's r correlation, and comparison to performance measures such as detailed exam scores. Through this analysis it was determined which measured homework behaviors were associated with high exam scores and course grades. It was also determined that homework problems requiring analysis can have an impact on certain types of exam problems where traditional homework does not. Suggestions are given for future research and possible use of these methods in other contexts.

Urban districts suffer from a severe shortage of qualified science teachers. Therefore, many new science teachers will need to take positions in urban districts with little or no exposure to urban communities. As a result, prospective teachers find it difficult to learn how to negotiate the cultural contexts of urban teaching. Consequently, it is essential for teacher preparation programs to begin to examine the cultural contexts of urban science teaching to understand how to support the personal and professional well being of novice urban science educators. Through in-depth phenomenological interviews this research documents the experiences, perceptions, and beliefs of veteran urban science teachers and how they navigated pathways to successful teaching careers. Results focus on how the cultural levels of teacher socialization (personal, institutional, and societal) shaped their induction into the teaching profession. In addition, the analysis of the data suggests that teacher preparation programs need to be reconceptualized to include a specific focus on culturally relevant and responsive pedagogy, teacher identity development, and how to develop community networks and connections. This restructuring is key for novice urban teachers to either increase their cultural sensitivity, or align their own cultural belief systems in-order to develop the necessary skill set to become successful urban science teachers.

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A thesis submitted to the Faculty of Education in fulfillment of the requirements for the Degree of Doctor of Education (Science Education) in the Department of Mathematics, Science and Technology Education at the University Of Zululand, South Africa, 2012. / This study sought to determine the conceptual difficulties experienced by grade 12 physical science learners with regard to mechanics. It also sought to identify the most prevalent alternative conceptions among grade 12 physical science learners in the area of mechanics, and develop interventions to alleviate the identified conceptual difficulties and alternative conceptions. In this regard, the study compared the effectiveness of a traditional lecture, outcomes-based education (OBE) and blended instructional approaches in alleviating or overcoming the identified conceptual difficulties and alternative conceptions concerning mechanics. The aspects of Mechanics dealt with in this study were: work and energy, motion on the inclined surfaces, projectile motion, force concept, static objects and Newton’s Third Law of Motion. In addressing the above research problem, the study developed and presented a theoretical and conceptual framework derived from the review of relevant literature, in line with the research questions of the study. The conceptual framework developed was based on the constructivist views of learning. A total of one hundred and forty (140) grade 12 physical science learners from Empangeni Education District were involved in this study. The study followed the quasi-experimental non-equivalent comparison-group research design. Though quantitative in design, the study also used qualitative research methods. Thus, both quantitative and qualitative data were collected. From the quantitative data, the findings showed highly statistically significant gains between pre- and post-test scores of OBE and blended approaches in particular. The average normalised gain score concept was also used determine the most effective instructional approach. Convenience sampling was used to select participating schools. A Test in Basic Mechanics (TBM) was designed to assess the learners’ understanding of the most basic concepts in mechanics. The TBM was administered both as a pre- and post-test to the three groups (traditional, OBE and blended groups) to determine the level of experience, knowledge, pre-existing alternative conceptions, level of understanding of basic concepts and principles on mechanics topics identified at the start of the investigation. As a pre-test, the TBM was also used to identify the specific conceptual difficulties and alternative conceptions in mechanics. The identification of the conceptual difficulties and alternative conceptions after the pre-test was followed by three instructional interventions (the traditional, OBE and the blended approach). The three interventions addressed the same mechanics topics mentioned above. These interventions were then followed by post-tests to ascertain the effectiveness of the interventions in addressing the identified conceptual difficulties and alternative conceptions, as well as any conceptual difficulties and alternative conceptions which were resistant to change even after the interventions. The results revealed that the learners experienced conceptual difficulties with regard to (a) resolving the components of the weight; (b) work concept; (c) work-energy theorem application; (d) kinetic energy concept; and (e) principle of conservation of mechanical energy application. Regarding the most prevalent alternative conceptions in mechanics, learners held eight alternative conceptions related to kinematical and dynamical concepts. Alternative conceptions held by the learners in mechanics concerned the following: (a) the acceleration and velocity of projectile motion; (b) weight/mass of an object as related to Newton’s Third Law of motion; (c) force concept; (d) objects in motion; (e) static objects; (f) Newton’s Third Law of motion; (g) acceleration of projectiles; and (h) active force. The average normalised gains for the traditional, OBE and blended instructional approaches were (g) = 0,20; (g) = 0,30; and (g) = 0,60, respectively. This confirmed the statistical analysis computed using One Way Analysis of Variance (ANOVA), that the blended instructional approach was the most effective instructional approach in alleviating the conceptual difficulties and alternative conceptions in mechanics. Qualitative data showed that most of the pre-existing conceptual difficulties and alternative conceptions appeared to have been alleviated, although not completely overcome by the interventions. There were statistically significant differences that were found among the traditional, OBE and blended instructional interventions. It is therefore noted that the blended instructional approach to teaching and learning can have a significant contribution to overcoming conceptual difficulties and alternative conceptions in mechanics, and the improvement of efficiency of learning. The study concluded that conceptual difficulties and alternative conceptions in mechanics could best be alleviated using the blended approach to teaching and learning. A number of recommendations were also made. Some alternative conceptions were resistant to change in the face of the traditional lecture based teaching. This meant that a more powerful teaching technique had to be devised. Thus, physical science educators should be encouraged to use the blended approach to teaching and learning in order to accommodate all learners in a class. Blended teaching and learning is mixing of different teaching and learning environments – mainly manifested in combining face-to-face instruction with the computer mediated-instruction. In one class of learners there are different learner characteristics. Learners learn in different ways like learning through lecture (telling), discussion, problem solving, practical work, discovering, experimenting, using pictures and diagrams, videos and demonstrations.

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The aim of this study was to describe co-construction processes in large group discussions. Co-construction, as used here, is a process by which the teacher and the students work together to construct and evaluate mental models of a target concept. Data were collected for an in-depth case study of a single teacher instructing middle school students with an innovative curriculum on human respiration. Data came from transcripts of video taped lessons, drawings, and pre- and post-test scores. Quantitative and qualitative analyses were conducted. In the quantitative analysis, differences in gains between one and two standard deviations in size were found between the pre- and post-test scores indicating that the students increased their understanding about human respiration. In the qualitative analysis, a generative exploratory method followed by a convergent coded method was conducted to examine teacher-student interaction patterns. The aim of this part was to determine how learning occurred by attempting to connect dialogue patterns with underlying cognitive processes. The main outcome of the study is a hypothesized model containing four layers of nested teaching strategies. Listed from large to small time scales these are: the Macro Cycle, the Co-construction Modes, the Micro Cycle, and the Teaching Tactics. The most intensive analysis focused on identifying and articulating the Co-construction Modes—Accretion Mode, Disconfirmation Mode, Modification Mode, Evolution Mode, and Competition Mode—and their relations to the other levels of the model. These modes can either describe the construction and evaluation of individual model elements or of entire models giving a total of ten modes. The frequency of these co-construction modes was then determined by coding, twenty-six hours of transcripts. The most frequent modes were the Accretion Mode and the Disconfirmation Mode. The teacher's and the students' contributions to the co-construction process were also examined. It was found that both the teacher and the students generated ideas in approximately equal proportion to build the models, that the teacher usually evaluated the ideas, and that both modified or disconfirmed the ideas. Thus the study is an attempt to develop a vocabulary for describing strategies that facilitate student model construction.