Catálogo de publicaciones - libros

In this paper, we introduce and exemplify aspects of a tool for analysing the various forms and functions of discursive interactions in high school science classrooms. This tool, or analytical framework, is based on a sociocultural view of teaching and learning, and consists of five linked aspects: . Here we focus attention on introducing and exemplifying how different teaching purposes can be addressed through combinations of communicative approach and patterns of discourse, as the scientific ‘story’ develops. In this way we demonstrate how the different aspects of the framework interrelate, providing a coherent basis for analysing classroom interactions. Finally we turn to the ways in which the framework has been used in science teaching and discuss how the framework is being used with science teachers in the context of professional development programmes, in both the UK and Brazil.

This paper aims at exploring the discursive activity of one group of second year biology students during their collaboration on a task of stating and testing hypotheses to answer a causal question. The specific task is a part of a didactic sequence that was developed in the context of genetic engineering considering aspects of situated-learning theory, with the aim of providing students the opportunity to ‘talk science’ with their peers as participants of a hypothetical gene cloning project. Our focus is set on certain cognitive aspects of peers’ discourse. Hence, this paper is concerned with the construction of arguments, particularly on the level of argumentative operations (e.g. claims, justifications, challenges) and the context-bound epistemic operations (e.g. abducting, appealing to instances) activated by peers in order to produce a joint answer to the task’s causal question. Furthermore, it is concerned with the development of the hypothetical-deductive reasoning pattern potentially involved in peers’ hypothesis-testing process.

The process of collaborative construction of arguments about environmental management by 11th grade students working in small groups is studied. The question explored is the evolution of the students’ positions and arguments along a sequence shaped around an authentic — and real — problem: the impact of a drainpipe in a wetland of high ecological value; whether students kept their initial positions or changed them and the corresponding reasons. The collaborative construction is explored in terms of the (Mortimer & Scott, 2003). The participants were the 37 students in an 11 grade group and their teacher (the second author). The sessions were recorded in audio and video, and the data also include the students’ portfolios and essays. In this paper the transcriptions are analysed and the arguments represented using Toulmin’s (1958) layout. The analysis shows changes in the positions of 22 students, either radical, from positive to negative assessment, or shifts to balanced views. The causes for the changes and the co-construction of arguments are also discussed.

Despite extensive research, our understanding of the teaching and learning of direct current (DC) electricity remains poor. As part of a larger project focused on learning outcomes and analogies/models/metaphors appropriate at different levels of electricity learning, in this study we investigated the detailed forms of explanations and analogies/models/metaphors used in senior high school textbooks in Victoria, Australia, and the understandings of the writers of these textbooks. All 3 authors had inadequate understandings of models and analogies, there was great variation in author understanding of voltage (with one author having clearly inadequate understanding), and the approaches authors used in their books reflected these inadequacies. We suggest that this serious issue is not specific to the state of Victoria.

This paper concerns interpretation and constitutive elements of understanding the world, both of which are treated in relation to the concept of force. Studies are criticized in which students’ conceptions are formulated, without further clarification, in terms of the word ‘force’. From such reports it can neither be concluded what students believe nor how their beliefs relate to science. Instead, reasons or criteria for applying ‘force’ need to be made explicit. Those reasons concern the effects that forces produce, namely deviations from an influence-free state; they also concern their sources, as made explicit in laws from which, for a given situation, the forces acting in it can be derived. The general concept of force, thus associated with the two-tier explanatory strategy of specifying (1) influence-free states and (2) force laws to account for deviations from those states, is a constitutive element of understanding the world. Within the constraints set by this explanatory strategy, the concept of force can still be variously applied, both in everyday and in scientific explanations. The differences between these various applications are partly anchored in distinct explanatory interest

The purpose of this study was to describe the evolution of conceptions about chemical equilibrium based on observations/interactions with selected chemistry students using an instructional design which included constructivist strategies such as POEs, analogies, small group discussions, and journal writing. Two intact classes with a total of 75 students enrolled in a general chemistry course participated in the study. The conceptual evolution of six students was followed through the use of pre-tests, transcripts of audiotaped and videotaped group discussions, written answers to activity sheets, learning journals, interviews, and post-tests. The students started with concepts of complete reactions and progressed to developing concepts of reversibility but had difficulty with the dynamic nature of reversible reactions. The use of an analogy using double-sided disks helped in the students’ visualization of the microscopic processes taking place and in the properties of systems as they approach and when they reach equilibrium. However, students’ conceptions of complete reactions still competed with their conceptions of reversible reactions.

The basic assumption, for which we try to provide evidence in this paper, is that students always use multiple explanations before and after teaching. Other studies also give evidence of competing conceptions used in one content area, yet often a variation of context is seen as the cause of multiplicity. The study presented here focuses on individual answers within one context. A total of 47 students from grade 7 up to university level participated in interviews which dealt with three qualitative tasks in the domain of force and motion. As the interview technique was based on waiting and asking questions of specification without giving additional information, the context is assumed to be stable when dealing with one task. Data interpretation focused on 27 students from four different schools (age 16), who were interviewed before and after they attended a class in mechanics. Results show that most answers, even with respect to one task, reveal multiple explanations.

This research describes a cross-sectional study, which will give insights into the development of students’ understanding of chemical kinetics (at key points, in relation to relevant teaching) from secondary to university level, in Turkey. The study is based mainly on the written responses given by school and undergraduate students to a series of written tasks involving concepts and phenomena in chemical kinetics. A small-scale interview study was also carried out with a number of students to obtain further information regarding students’ ideas about chemical kinetics and to check for appropriate interpretation of the written responses. In this paper, our focus is on the students’ understanding of the relationships between the concentrations of reactants/products and reaction rate. Analysis of students’ responses on written probes and in interviews indicates that, after instruction, many students use conceptions not consistent with scientific perspectives, and have conceptual difficulties in understanding the relationships between concentration and reaction rate. Furthermore, the results show that students did not frequently use “particulate” and “mathematical” modelling, and in most cases such modelling was not used as intended by the curriculum. The results indicate a need to review curricula, and instructional practices, in the light of the students’ difficulties in understanding chemical kinetics.