In this study we investigated junior high school students' processes of argumentation and cognitive development in science and socioscientific lessons. Detailed studies of the relationship between argumentation and the development of scientific knowledge are rare. Using video and audio documents of small group and classroom discussions, the quality and frequency of students' argumentation was analyzed using a schema based on the work of Toulmin (1958). In parallel, students' development and use of scientific knowledge was also investigated, drawing on a schema for determining the content and level of abstraction of students' meaning‐making. These two complementary analyses enabled an exploration of their impact on each other. The microanalysis of student discourse showed that: (a) when engaging in argumentation students draw on their prior experiences and knowledge; (b) such activity enables students to consolidate their existing knowledge and elaborate their science understanding at relatively high levels of abstraction. The results also suggest that students can acquire a higher quality of argumentation that consists of well‐grounded knowledge with a relatively low level of abstraction. The findings further suggest that the main indicator of whether or not a high quality of argument is likely to be attained is students' familiarity and understanding of the content of the task. The major implication of this work for developing argumentation in the classroom is the need to consider the nature and extent of students' content‐specific experiences and knowledge prior to asking them to engage in argumentation. © 2007 Wiley Periodicals, Inc. J Res Sci Teach 45: 101–131, 2008

Teachers' professional knowledge is assumed to be a key variable for effective teaching. As teacher education has the goal to enhance professional knowledge of current and future teachers, this knowledge should be described and assessed. Nevertheless, only a limited number of studies quantitatively measures physics teachers' professional knowledge. The study reported in this paper was part of a bigger project with the broader goal of understanding teacher professional knowledge. We designed a test instrument to assess the professional knowledge of physics teachers (N = 186) in the dimensions of content knowledge (CK), pedagogical content knowledge (PCK), and pedagogical knowledge (PK). A model describing the relationships between these three dimensions of professional knowledge was created to inform the design of the tests used to measure CK, PCK, and PK. In this paper, we describe the model with particular emphasis on the PCK part, and the subsequent PCK test development and its implementation in detail. We report different approaches to evaluate the PCK test, including the description of content validity, the examination of the internal structure of professional knowledge, and the analysis of construct validity by testing teachers across different school subjects, teachers from different school types, pre-service teachers, and physicists. Our findings demonstrate that our PCK test results could distinguish physics teachers from the other groups tested. The PCK test results could not be explained by teachers' CK or PK, cognitive abilities, computational skills, or science knowledge. ARTICLE HISTORY

No abstract

No abstract

No abstract