"Context sensitivity" is a core issue in physics education research (PER). Why does student understanding of a concept depend so crucially on the context in which it is embedded? This dissertation attempts to answer this question by using a variety of theoretical tools to model understanding. We conducted three empirical studies which probed context sensitivity of student understanding of (i) Vector Addition; (ii) The FCI (Force Concept Inventory); and (iii) the learning of the concept of a Mathematical Group. (i) Regarding vector addition, we discovered context sensitivities involving the type of physical quantity added (e.g. force or momentum); the textual prompts "total", "net" and "resultant"; and the object on which a force acts. (ii) In the FCI, we discovered a moderate context sensitivity to unfamiliar words (i.e. when familiar words like "box" were substituted for unfamiliar words like "kist".) This sensitivity was moderately correlated with the difficulty of the question. (iii) Previous studies have shown that learners exhibit a sensitivity to the concreteness of the learning condition of a Mathematical Group; our study shows that students are engaged in different types of activity in these conditions. A variety of theoretical tools from PER, Cognitive Linguistics, Cognitive Psychology and other areas of Education Research are used to model student understanding in these various studies. Three key insights emerged. (a) The importance of one's model of "concept" - how it relates to the notion of "context", and how one chooses an appropriate grain size. (b) The difference between "expert" and "novice" - how this difference influences one's model of "concept", and how it influences one's notion of "sameness" and "difference". (c) Student reasoning - how a framing of a situation might result in fast, associative, linguistic reasoning on the one hand, or slow, deliberate simulative reasoning on the other. Finally, this thesis is grounded in Wittgensteinian ordinary language philosophy which maintains that notions of "concept", "context" and "understanding" obtain meaning not be referring to some transcendental "thing", but by being embedded in our messy form of life. In other words, by modelling understanding we are not approaching the "true meaning" of the term. Instead we are demonstrating how our various models are constitutive of what we mean when we say: "My students understand this concept".

Many studies have shown that students (at both school and university) have difficulties in understanding the concepts associated with DC circuits. Two competing theoretical frameworks have been advanced to explain these problems: "misconceptions" and "knowledge-in-pieces". The former is based on the assumption that student ideas are unitary, static and independent of context, while the latter considers student ideas to arise dynamically from flexible combinations of "pieces of knowledge" and that a particular combination of pieces is primed by the context presented. The present work explores the extent to which student responses change as a result of small, fine-grained changes to a simple open circuit with only three components: a battery, a single wire and a resistive element. Three different types of resistive element were used: a light bulb, a heater and a resistor. A previously piloted, eight-question written instrument, consisting of both forced choice responses and free response writing, was administered to two cohorts of non-major, first year physics students from different institutions. The results, consistent across both cohorts, confirmed that context (e.g., type of resistive element used) was critical in triggering student responses. Student reasoning varied widely, and the majority of students used more than one "foothold idea" on which to base their explanations. Only 10% of the combined cohort got all answers (canonically) correct, and all of these students used only the single idea of "loop continuity" as the basis of their explanations. Based on the written responses, and a small number of clarifying interviews, it was clear that sense-making was a key driver in student reasoning. However, either (a) an incorrect explanatory interpretation of a prior experience, or (b) the absence of any experiences from which to extract a key abstract concept, such as "loop continuity", lead to incorrect (canonical) answers. One implication of the findings is that, unlike mechanics, where prior concrete experience is used as the starting point and then refined toward abstract knowledge, it appears that starting with the abstract might be a more effective pedagogical approach. This stands in contrast to many curricula that start with a concrete instantiation such as the light bulb.

Includes bibliographical references. / For the public to be able to participate meaningfully in debates regarding issues that are related to science and technology it is important that they are properly informed and that their sources of information are reliable. One source of such information are university science students and it is therefore interesting to find out what their views are regarding various scientific concepts. For example such an area of interest is that of using nuclear power for electricity generation, in particular the dangers associated with radiation. A reasonably correct view of radiation would be seen as an important part of having a meaningful debate. The present study aims to find out the views that a group of university students who are studying physics hold about radiation, in particular their immediate response to being asked to clarify what the term radiation means. However, the notion that students simply have conceptions that are unitary and static has been challenged by several Physics Education Researchers. Instead a view summarised as “knowledge in pieces” has been proposed in which it is suggested that much smaller units of ideas are brought together dynamically depending on the situation at hand and that context plays an important role in how students respond to questions. Thus, the thesis explores to what extent context plays a role in their responses by preceding the question with four different scenarios which are suggested as the contexts in which the question is being asked. In summary, the guiding questions for the present work are: (1) What do students understand by the term radiation and (2) To what extent do student response patterns depend on “textual priming”. The thesis is divided into two parts (1) a pilot study in which the methodology is established and (2) a follow up study (main study) in which the effect of textual priming on the responses is explored.

The laboratory environment can prove to be a complex space, with its potential to foster scientific sense making abilities in students. One cause for concern is the frequent physics tearoom discourse that students do not like physics laboratories. However, before attempting to address this issue, it is necessary to establish to what extent it is true and then to probe the issues that might underlie such perceptions. The present study, part of a larger program that is aimed at probing student views with regard to the lab experience, describes (a) the development of an instrument that probes students' perceptions of lab engagement and (b) the results of a selected subset of the data as detailed below. A written instrument, the Physics Perceptions Lab Questionnaire (PPLQ), was designed to probe the following five areas: expectations of labwork, enjoyment of labs, the perceived degree of personal learning that took place, the perceived association between lectures and lab activities, and views about the relationship between experiment and theory. Each of the five questions that made up the PPLQ was constructed in the form of a debate in which different views were declared. Thus, the data that ensued were of two types: (1) a Forced Choice Response (FCR), and (2) a Free Writing Response (FWR). The FCR data were analyzed by tallying the various choices made for each question, while the FWR data were analyzed using a grounded approach. The PPLQ was administered to 100 first year physics students at the University of Cape Town, after they had completed four weeks of the lab course. The focus of the present work is on the results obtained for the (a) Enjoyment and (b) Learning probes, and thus the analysis and results of the FWR data are limited to these two questions. The FCR results of the two probes on which the present study is focused (Enjoyment and Learning) indicated two opposing trends. While the majority of respondents felt that they had indeed learnt a great deal from the labs, this largely positive outcome for learning did not translate into a positive perception of enjoyment of labs. In contrast, the majority of the respondents indicated that they had not enjoyed the labs. The grounded analysis of the accompanying FWRs led to the emergence of 15 reasoning categories. The categories are grouped according to their nature of being intrinsic and extrinsic to the laboratory task and also translate to being internal and external to the students' locus of control. In addition, each individual reason that was provided indicated a Positive (P) or Negative (N) Impact on engagement. The data were thus also coded for P or N impact. To improve the quality of engagement would thus require a collective effort that takes into consideration the link between cognition and emotions along with framing, as they encompass together the issues intrinsic and extrinsic to the lab task.