Introduction

Classrooms are among the most familiar learning contexts in Western society. Their impact on society has been formidable. However, besides definitive successes such as democratizing access to knowledge, the constraints that classrooms arise to learning have engendered many criticisms. One constraint concerns the socio-spatial structure of classrooms that leads teachers to function as isolated individual practitioners. A bureaucratic and institutional constraint concerns the temporal structure of discrete lessons and short time sequences of work, punctuated by tests and exams. Another constraint is motivational: Attaining grades is a main motive for school work which leads to classification of students into categories such as weak, competent, passive, etc. These constraints and many others have moulded recurrent learning practices such as lectures administered by the teacher, teacher-led plenary discussions, or drill-and-practice individual activities. The current research literature on classroom interactions takes into consideration the complexity of classroom constraints and practices. Many of the perspectives adopted function as snapshots that help understanding the processes involved in classroom interaction: the process-product perspective helps correlating between teachers’ actions and students’ further outcomes; the ethnographic perspective helps comprehending how classroom practices enact and build culture; the discourse-analysis perspective focuses on how classroom practices and discursive events shape each other. These and other perspectives generally take the classroom context as a given in which the changes that may occur leave this context almost intact. This book is not characterized by one perspective shared by all contributors. Unity comes from the fact that researchers belong to a common adventure – changing school practices and norms. This adventure is moved by societal ideals of reason and equity. Contexts for learning are not immutable givens. Rather, the classroom context is the result of a programmatic design: researchers are interested in implementing certain practices or instilling certain norms. Practices instigated include small group collaborative problem solving, non-intrusive guidance (also called moderation) in group discussion, or collective argumentation, to cite a few. By doing so, all authors share a critical perspective that aims at supporting change at all levels (institutional, curricular, communicative, material). The authors also adopt a common dialogic approach in their striving for change that denies a radical deconstructive stance. Typical dialogic actions

include the instigation of new evaluation practices to instil new norms (at the institutional level), the negotiation of new contents (at the curricular level), the implementation of interactive practices (at the communicative level), and the elaboration of new (technological) tools that support productive constructions. The theoretical tenets of most of the contributors stem from socio-cultural psychology as well as from constructivism. They often refer to activity theory to trace changes that involve all the levels cited above among researchers, designers, teachers and students. We chose the term transformation for the title of the book to indicate that the changes most of the contributors describe have a historical dimension. Transformation concerns tools as well as individual or collective outcomes. If the English language had permitted it, we would have labelled what we study and are engaged to foster as ‘transformation of knowing’ (instead of ‘transformation of knowledge’). The terms that fuel our quest for tracing and fostering transformation in classroom interaction include actions, shared understanding, intersubjectivity, argumentation and especially succession of activities. The transformation concerns both the community and the individual; we focus on changes of (communal) practices and of identity. The transformations we attempt to trace encompass moments of unequal importance, and the authors seek to identify the most crucial ones (designated differently by different authors – constructions, epistemological discontinuities, breakdowns between intra-and intersubjective processes, knowledge creation and so on); these impinge on further actions or on further successive activities. Our focus on transformation in special moments of classroom interactions as well as in successions of activities necessitates the adoption of a multi-level of analysis (micro, meso and macro). The coordination of these different levels is not easy since it is natural at a micro-level to analyse discursive events, but at a macro-level other perspectives are necessary. The multilevel invites then a multiplicity of methods that are not always compatible. Methodological efforts are thus necessary to resolve tensions between, for example, construction of knowledge within activities and learning processes in successive activities, or the relations between shared and individual understandings. The dialogic approach that characterizes most of the contributions necessitates researchers to engage in activities with teachers, students, designers, educators and, in some cases, policy makers. The researchers are then insiders and, as such, consider the specificity of the transformations which are bonded to the norms of discourse, knowledge structures and objectives of the domain taught. The focus on mathematics and science classrooms helps, we hope, in studying indepth specificities, for example, classroom interactions in which participants engage in mathematical abstraction or scientific hypothesizing. The book is organized in five parts. The first part provides contributions on construction of knowledge. Schwarz, Dreyfus and Hershkowitz (Chapter 1) present the nested epistemic actions model for studying mathematical abstraction in classroom contexts. This chapter has a practical character in the sense that it provides tools for describing the emergence of abstraction and its consolidation. The authors stress the utility of this model to describe what they consider fundamental in mathematics classrooms, a construction through vertical reorgan-

ization of previous constructs. This process that the authors call ‘abstraction in context’ is driven by a need. It becomes known through three basic epistemic actions (recognizing, building-with and constructing) whose emergence involves interactions between tasks and activities. Tiberghien (Chapter 2) proposes and illustrates a theoretical framework to characterize high school physics classrooms by establishing relationships between what is taught and what is learned. She defines the fundamental idea of ‘taught knowledge’ as the researcher’s (re)construction of joint productions of the teacher and the students in a physics classroom to trace students’ evolution of performances before and after mechanics teaching sequences through relations established between taught knowledge and students’ activities in the classroom. Tiberghien analyses at different levels of analysis how ‘conventional meanings’ are interwoven in classroom activities. While the first two chapters mainly encompass micro-and meso-levels, Yerushalmi (Chapter 3) adopts a macro-level perspective. She uses the notion of epistemological discontinuity as a design principle that indicates expected difficulties in long-term learning. She exemplifies the design of an algebra curriculum at a point of discontinuity to demonstrate why the use of technology has the potential to introduce strengths that make the ‘unnatural’ look ‘natural’. However, Yerushalmi suggests that known discontinuities are generally stable because they indicate an epistemological gap. She then suggests that identifying critical discontinuities is crucial for studying student constructions of knowledge and analysing classroom guided inquiry supported by technology. Hakkarainen and Paavola (Chapter 4) propose a useful metaphor for learning, the trialogical learning metaphor, which is more appropriate than the acquisition (or knowledge construction) and the participation metaphors in activities in which students collaborate to construct an outcome, especially when this outcome is material, reused in following activities as an artefact, and when the collaboration is mediated by technological tools. They exemplify three cases in which the trialogical metaphor usefully portrays gains of individuals and groups in joint activities. In their commentary on the first part, Kidron and Monaghan compare different theories underlying the chapters. They establish links to some additional theories including the theory of didactic situations. They then point out the importance of considering epistemology, pedagogy and teaching, and need and anticipation in theories on knowledge construction, and show how the four chapters fare on this account. They similarly look at how the four chapters deal with the quandary of individual versus social construction of knowledge. And they end by asking to what extent these chapters together contribute to a consistent wider understanding and analysis of knowledge construction. The second part of the book is dedicated to guidance in construction of knowledge. In the three chapters of this part, the authors stress that the role of guidance is delicate to play since it can easily undermine understandings constructed by individuals or by groups. On the other hand, they see unguided group work as clearly insufficient for learning in science or mathematics classrooms. The question is then under what conditions can expertise and group activity be productively combined.