Digital artefacts as representations: forging connections between a constructionist and a social semiotic perspective Professor Candia Morgan (corresponding author) Institute of Education, University of London 20 Bedford Way London WC1H 0AL United Kingdom c.morgan@ioe.ac.uk and Professor Chronis Kynigos Educational Technology Lab, National Kapodistrian University of Athens, Greece Abstract: This paper uses the methodology of cross-case analysis to clarifying connections and differences between two specific conceptual frameworks, multimodal social semiotics and constructionism, in particular in the ways they each deal with the idea of representation. It builds especially upon the idea of ‘distance’ of digital representations with respect to usual representations, stressing the multidimensionality of this notion and possibilities for progress towards a shared framework for research about representations. The paper focuses on the crosscase analysis study of a ‘middle distance’ dynamic digital artefact, MoPiX, by two teams sharing a common reference framework (constructionism), but with distinct views with regard to representations. The research yielded a distinction in the ways connections between representations are valued by the two approaches and their respective interpretations of meaning generation. Keywords: constructionism; social semiotics; multimodality; representation; cross-case analysis; theory networking 1 Digital artefacts as representations: forging connections between a constructionist and a social semiotic perspective Candia Morgan, Institute of Education, University of London, United Kingdom Chronis Kynigos, Educational Technology Lab, National Kapodistrian University of Athens, Greece Abstract: This paper uses the methodology of cross-case analysis to clarifying connections and differences between two specific conceptual frameworks, multimodal social semiotics and constructionism, in particular in the ways they each deal with the idea of representation. It builds especially upon the idea of ‘distance’ of digital representations with respect to usual representations, stressing the multidimensionality of this notion and possibilities for progress towards a shared framework for research about representations. The paper focuses on the crosscase analysis study of a ‘middle distance’ dynamic digital artefact, MoPiX, by two teams sharing a common reference framework (constructionism), but with distinct views with regard to representations. The research yielded a distinction in the ways connections between representations are valued by the two approaches and their respective interpretations of meaning generation. Introduction This special issue addresses the problem of fragmentation of theoretical frameworks and constructs in the context of the use of digital media in mathematics education. This fragmentation has resulted in polysemous use of terms and notions, difficulty in using constructs across educational contexts and a sense of noise in the growth of knowledge in the field (Kynigos & Lagrange, this issue; Artigue, Cerulli, Haspekian & Maracci, 2009; Prediger, Bikner-Ahsbahs & Arzarello, 2008). The papers aim to contribute to the production of and experience with tools and methods for the networking amongst frameworks and constructs. The notion of networking and the ensuing agenda in the mathematics education community has been given serious attention (Prediger et al, 2008) but has taken on a range of different meanings. In this issue it is being used in the sense of the forging of connections (Mariotti & Artigue, this issue, Artigue et al, 2009) and the recontextualization that occurs when theories and constructs are put to use in designing and studying educational practices (Lagrange & Kynigos, this issue). This paper addresses a key 2 feature of the affordances and the uses of digital media: mathematical representations. The nature of representations, their affordances, their uses and the respective relation with meaning generation has given rise to frameworks and constructs, themselves a part of or connected with more general frameworks in mathematics education (e.g. Dreyfus, 1994; Font, Godino & d’Amore, 2007; Kaput, 1991; Radford, 2009). In this paper we do not attempt to review all approaches to representations but rather we discuss the use of crosscase analysis, a cross-experimentation methodology pervading this special issue, as a tool to forge connections between two particular approaches to representation, the multimodal social semiotic approach and the constructionist approach. We narrow down our lens precisely in our attempt to better understand what light two compatible but different approaches can shed on inquiry into didactical phenomena in the context of the use of digital media and what precisely is the commonality and the distinctiveness between them. The idea of representation has held an important place within the field of mathematics education for several decades, as is evident in the extent of literature addressing it (e.g., Cobb, 2000; Duval, 1999; Goldin, 1998; Janvier, 1987; Vergnaud, 1998). With the development of new technologies, a particular focus has been developed on new forms of representation afforded by the technology (e.g., Ainsworth, Bibby, & Wood, 1997; Borba & Villarreal, 2006; Edwards, 1998; Falcade, Laborde, & Mariotti, 2007; Morgan, Mariotti, & Maffei, 2009; Noss & Hoyles, 1996; Yerushalmy, 2005). Two characteristics of representations with digital technologies are considered especially significant for mathematics education. The first characteristic is the possibility of linking different semiotic systems, for example algebraic expressions and Cartesian graphs, in such a way that manipulation within one system effects a corresponding change in the other. This linking of multiple representations of the ‘same’ mathematical object is seen to have potential to enrich students’ conceptualisations. The second significant characteristic is the possibility for representations to have a dynamic element. As such representations are manipulated by students, the manipulation and the ensuing changes become part of the representation itself, again enabling new forms of mathematical conceptualisation to develop. New modes of communication and new means of interaction have thus emerged, both between students and the technological artefacts themselves and between students 3 and mathematical ideas. There is, however, a wide range of different ways in which researchers conceptualise ‘representation’, not only drawing on different theoretical frameworks but also focusing on different types of phenomena. As is evident in its title, the ReMath project (Representing Mathematics with Digital Technologies)i took as its starting point a recognition of the significance of representation in the development and use of new technologies in mathematics education. However, there was no initial shared theoretical conceptualisation of the idea among the participating teams. As discussed in Morgan et al. (2009), the maximal common agreed definition of representation adopted at the start of the project was simply “something which stands for something else from someone’s point of view”. This sparse definition proved sufficient to form some useful distinctions. In particular, the agreed recognition that any discussion of representations must take account of the context within which they are situated (that is, considering the point(s) of view of the “someone(s)” for whom they are representations of something), allowed us to develop a refined notion of “distance” as a characteristic of the external representations offered by digital technologies, identifying different dimensions (epistemological and social) along which teachers, students and researchers might experience such representations as “near” or “far” from the traditional school mathematics with which they are familiar (Morgan, et al., 2009). Recognition of the extent of differences between our various theoretical orientations towards representation was important in that it allowed us to develop and use a shared language coherent with all our perspectives. This shared language did not imply that we also developed shared theoretical perspectives but that we became more able to communicate about our perspectives in a way that made similarities and differences explicit. Our agenda with respect to representations was part of an important general aim of the project: to attempt to build an integrated theoretical framework that would allow a deeper and more productive conversation between researchers with different theoretical starting points. In this article, we seek to illustrate the process of integration and some of its outcomes through looking in detail at a cross-case analysis of a single example, bringing into conversation the perspectives of teams of researchers from two institutions, the Institute of Education, University of London (IOE) and the Educational Technology 4 Laboratory, University of Athens (ETL). The “cross-experimentation” methodology, initially conceived during the TELMA project (see Bottino & Kynigos, 2009) and used as a central method of ReMath, was further developed to use cross-case analysis as a means of producing this conversation. In the next section, we present the initial theoretical orientation towards representation of each team. We then discuss the crossexperimentation carried out by these two teams using a digital technology, MoPiX, developed by the IOE team. This experimentation produced data from two distinct contexts that were analysed by each team from its own theoretical perspective. The consequent analyses then served as a focus for reflection between the two teams. We offer an example of this cross-case analysis and discuss how it provided a basis for clarifying the similarities and differences between the ways in which the two teams conceptualised representation and for moving towards an integrated framework that would enable us to share our research methods and outcomes more effectively. Representations IOE perspective: The IOE team adopts a multimodal social semiotic perspective on representation (Halliday, 1978; Hodge & Kress, 1988; Kress & van Leeuwen, 2001). From this perspective, the elements of spoken, written, diagrammatic or other forms of communication are not taken to have a fixed relationship to specific objects or concepts or to indicate any internal intention or understanding on the part of the author. Rather, the resources offered by language, diagrams, gestures and other modes are considered to provide a potential for meaning making. The term representation cannot therefore be taken to have an internal reference to some individual mental image or structure. Nor can it be taken to refer to a determined relationship between signifier (word, picture, symbol, etc.) and signified (represented object or concept). As the elements of communication acquire meaning in interactions within social practices, the notion of representation must also be understood relative to specific social interactions and practices. When considering representation within mathematics and mathematics education practices, there are formal systems of words, diagrams, algebraic notation etc. that are used 5 in conventional ways in relation to mathematical constructs. For example, within such practices an algebraic expression ax 2 + bx + c and a parabola may both be used as forms of representation of the construct quadratic function (of course the words quadratic function may themselves be considered a further form of representation). These different forms of representation, using different modes of communication, have different potentials for meaning making. For example, an algebraic expression may orient participants in the practice of mathematics education towards possible symbolic manipulations, e.g. substituting numeric values or factorising, whereas a graphical representation may orient participants towards specific visual features, e.g. minimum or maximum point; intercepts with the axes; gradient. (See O’Halloran (2005) for a detailed social semiotic analysis of the meaning potentials of these different modes.) However, as a representation can only be interpreted within the context in which it is being used, this context, the resources it provides and the resources that participants bring to the interaction from wider contexts must be taken into account in analysing how representations function in a given interaction. This conceptualisation results in an analytical focus on episodes of interaction, tracking the functioning of particular forms of representation in relation to other forms and to the multimodal interaction as a whole. ETL perspective ETL adopts a constructionist perspective where epistemology is at the centre, accompanied by a theory and a style of pedagogical design and learning process (Kynigos, 2012). The role of representations is important in the sense that they are perceived as integral components of artefacts-under-change and as a means for expressing, generating and communicating meaning. The nature of representations and the kinds of use to which they are put are at the centre of attention to the extent to which they play a significant part in a constructionist context, i.e. where verbal, written communication goes together with communication through tinkering with digital representations which are also perceived as artefacts. Constructionist artefacts can embody a wide range of complexity and have been perceived and analysed as representations themselves (Edwards, 1998). Both the structure and the functionality of the artefacts are important for the learning process. Some connections can be made by Edwards' distinction between structural and functional 6 perspectives and the artefact-instrument distinction made by Vérillon and Rabardel (1995). When a representation is put to use, precisely because it is seen as malleable, the meanings conveyed change along with changes made to the representation itself. Unlike the social semiotic perspective, digital artefacts are seen as representations designed by pedagogues to embed one or more powerful ideas. At the same time, in a constructionist setting, representations are not seen simply as objects to which some kind of meaning may be attached but as artefacts for tinkering with. In a typical situation, you would have humans dismantling an artefact, or improving it, or using it as a base or a building block to create more complex structures, or simply considering it as a base from which to build something different. So, the mathematical construct of quadratic function, to take an example from the previous section, can be represented textually, by means of a mathematical formalism, by means of a formalism within a programming language or by means of a model of something created by such a functional relationship (such as a trajectory of a projectile in a Newtonian space with gravity). In all cases, the attention is on what is being tinkered with. Meaning is generated through the use of the artefact but is also shaped by the representation itself. The representation plays the role of an important element of a learning environment which is dense in opportunities to generate meanings around a concept originally designed by pedagogues. It does allow for surprise, i.e. students generating unexpected meanings and uses of the representations and in fact it often welcomes creative and original meanings. However, there is didactical intentionality as to the kinds of meanings that may emerge: the design of the learning environment and of the representations within it are intended to support specific learning objectives. As representations are seen as expressions of meaning, the ways in which representations are manipulated also represent meaning. Writing an equation and then continually changing its parameter by means of a slider is a particular type of representation of continual change or rate of change between two variable values. Clicking on an object in order to perform an action on that object is also an expression of meaning. Finally, also in the core of the ETL perspective, was the idea of malleable artefacts as representations. In line with the constructionist perspective, artefacts are considered not as entities with fixed properties but as objects under change and in use. The activities of discussing behaviours, 7 planning and implementing changes and engaging in continual tinkering of the artefacts are integral parts of learning. In the same sense, representations are seen as directly linked or integral parts of the artefact. Comparing the two perspectives An important distinction between the perspectives of the two teams lies in their approach to the cognition of individuals. While both teams conceive of learning as something that happens in social interaction, the IOE’s perspective only allows one to speak of learning in terms of changes in patterns of interaction, without any move to take such changes as evidence of changes in individual cognition. On the other hand, ETL perceives cognition as the generation of meaning within a complex context of communication and construction. The attention is on studying what meanings are generated, how they are connected to and emerge from the situation at hand (see Noss & Hoyles, 1996) and how they evolve through these interactions. Another distinction is the role attributed to representations in the learning process. The ETL use of the notion of ‘tinkering’ with specially designed representational artefacts identifies a specific form of student activity that is theorised to be conducive to learning about the structure of the represented construct. The IOE on the other hand does not privilege particular forms of representation, seeing them all as resources that are available to students to make meanings. The focus of the IOE team’s research is on exploring the kinds of meanings facilitated by the multiple resources available to students. The IOE approach conceives of learning as changes in patterns of interaction rather than as intra-personal changes. From this perspective, the adoption and use of new representations in communications within mathematical contexts is a form of learning. The ETL perspective considers the extent to which a specific representation, and the ways it is connected to others, is conducive to the generation of meanings. A given representation such as formalism, which in the pre-digital era may have been an obstacle to meaning generation for children, may in some cases have been intentionally included in a digital expressive medium so as to be used in a meaningful way. Formal and traditional mathematical representations thus become texts that may be interrogated and new forms 8 of representations are sought and considered. ETL thus focuses on ways in which traditional representations can be put to use as for example when mathematical formalism becomes a programming language connected with graphical representations to construct parametric models. Cross-experimentation and cross-case analysis study The ReMath project used the methodology of “cross-experimentation” (Bottino & Kynigos, 2009) as a means to investigate the ways in which the representations offered by digital artefacts designed for learning and teaching mathematics function in mathematics classrooms and to support the communication between different teams of researchers. Use of this methodology recognises and takes account of the fact that the context within which classroom experimentation takes place and the theoretical frameworks used by the researchers affect the conduct and the outcomes of the research. In brief, two research teams, working in different contexts, each devise and conduct a programme of classroom research using the same digital artefact designed by one of the teams. A common research question is agreed, but must then be made specific by each team, according to their particular interests and theoretical frameworks. A set of instruments is used to gather information from each of the teams before and after the classroom implementation, enabling a careful elaboration of: the principles underpinning the design of the digital artefact; the didactic functionalities (Artigue et al., 2009) of the artefact attended to by each team; the local and global context in which each classroom experimentation takes place; the pedagogical plan used in each classroom; the data collected and methods of analysis. In elaborating these details of the methods used, each team makes explicit the ways in which the context of their research and their theoretical orientations affect the design and conduct of the research. Having conducted such cross-experimentation, the analyses of data conducted by each team of researchers are recognised to be strongly located within their separate contexts. An important part of the context is the theoretical framework employed by each research team. Understanding the role of context in the analysis is partly enabled by the rigorous specification of context provided by the cross-experimentation instruments. Each team’s 9 specification of the role of theories in their analysis, however, while clarifying and justifying the production of the research outcomes, is not sufficient to allow us to consider fully the question of the impact of the theoretical perspective. In order to explore this issue more deeply and to develop a fuller understanding of the similarities and differences between our various perspectives a cross-analysis study was conducted. In this crossanalysis study, each team chose a selection of data and its analysis from their own experiment. The data were re-analysed by the other team, using their own theoretical perspective, drawing on all the contextual information provided by the crossexperimentation. The two analyses then provided an opportunity for reflection on the similarities and differences between the perspectives and, importantly, on the ways in which apparently similar constructs (such as in this case representation) are used. The cross-analysis study methodology thus enables not only richer insights into the data but also a means of articulating the theories more precisely. We use the word articulating here with deliberate awareness of its dual meaning: both defining the connections between the perspectives and speaking each of the perspectives more clearly by developing our understanding of the ways its constructs are used. MoPiX software: description and design principles The example presented in this article involved the use by teams based in London (IOE) and Athens (ETL) of the digital artefact MoPiXii. MoPiX was designed by the IOE team as an exploratory environment for constructing animated models using the principles of Newtonian motion. The objects of the MoPiX microworld were designed to behave in mathematically coherent ways, providing an environment that, by exploring and building models within the microworld, was intended to allow students to construct orientations to concepts such as velocity and acceleration consistent with conventional mathematical and physical principles. The MoPiX microworld consists of objects whose properties are determined by sets of equations. The basic properties include shape, colour and position (defined by values of Cartesian coordinates). The equations determining these properties can include a time parameter, thus enabling change in e.g. position over time. A library of equations is provided as a starting point for users, including sets of equations that will cause an object 10 to move with a given velocity and acceleration. Other equations in the library include ones which detect whether an object is in a given position (e.g. “hitting” the side of the screen or another object). Conditional operators can be used within equations, thus allowing, for example, a change of direction if a moving object “hits” another. Users can edit these equations or create new ones in an editor. Objects and models (objects and their associated equations) may be saved to a central server where they are immediately available to all other users. An object in its initial state appears as a small black square. It can be “created” by dragging it onto the “stage” - the part of the screen where the animated model is constructed and set in motion. Equations are then assigned to the object by dragging and dropping and these equations are implemented by “running” the model. Although the motion of animated objects on the screen appears continuous, the equations model velocity and acceleration by discrete incrementation over time of position and velocity respectively (see Figure 1). ---- insert Figure 1 about here ---The IOE team’s multimodal social semiotic framework discussed above informed the design of MoPiX (see Bezemer & Kress, 2008 for a discussion from this perspective of issues involved in design of pedagogic texts). This theoretical framework highlights the different potentials for meaning offered by different modes of representation. Each mode involves its own distinctive system of elements, grammar and meaning potential. Moreover, interaction between such different modes creates further opportunities for meaning making. MoPiX was thus designed to provide a multi-semiotic environment with rich potential for making meanings drawing on multiple resources, including those occurring in the wider social environment of its useiii. In particular, MoPiX links a formal notation of equations with visual animated models. The trace of motion of an animated object can also be perceived as a Cartesian graph. However, social semiotics is not a theory of learning. While it can suggest how students may make sense of the multimodal texts they experience in the classroom and hence suggests some characteristics of good learning environments, it is not sufficient by itself to inform the design of activities for learning. The design of MoPiX was also influenced by a 11 broadly constructionist theoretical frame. The constructionist approach to learning (Harel & Papert, 1991; Kafai & Resnick, 1996) promotes investigation through the design of microworld environments. MoPiX was conceived as a constructionist toolkit (Strohecker & Slaughter, 2000), a dynamic visual environment that supports construction activities in social contexts, based on these constructionist principles. Learners use the fundamental elements of the microworld (equations and objects whose properties and behaviours are defined by the equations assigned to them) to build objects and models with new sets of properties and behaviours. They may then activate their constructions to investigate them, forming and testing hypotheses about their behaviours. While the ideas of both multimodal social semiotics and constructionism provided principles for the design of MoPiX, the IOE team involved in the cross-experimentation did not draw on constructionism, rather conceiving of their research only from the multimodal social semiotic perspective. On the other hand, the constructionist design principles fitted the constructionist framework of the ETL team. Besides the general constructionist design principles already embedded in MoPiX, the ETL team focussed on specific aspects of the representations such as the concern to find a meaningful use of mathematical formalism and the different ways in which representations can be manipulated. ‘Distance’ of MoPiX representations Morgan et al. (2009) adopt the term distance to describe the extent to which teachers and students may experience the representations provided by a piece of software as different from or similar to the familiar representations used in their classrooms. Representations embedded in digital media are characterised by their inter-connectivity and the ways in which they can be manipulated dynamically. Both these characteristics have potential to increase distance. The representational elements of MoPiX are compatible in some ways with traditional mathematics semantically and syntactically but also differ in significant ways from the traditional repertoire. For example, there are semantics for handling time and position and for handling specific properties of objects such as colour. The formalism of MoPiX has some similarities to traditional mathematics, but it also has characteristics which transform it into a programming command. A further important aspect of the distance of MoPiX representations from familiar classroom representations is connectivity. 12 MoPiX mathematical formalism is inextricably connected to graphical representations of objects, including both features of their appearance and the nature of their movement, which can be perceived as physical objects or as strictly mathematical objects according to the properties given to them and the field in which they exist. Lastly we consider what Morgan et al. (2009) call curricular distance: the relationship between the ways MoPiX may be used and the content and methods of the usual curriculum. In particular, we note the role of formalism in MoPiX to describe and control the properties and behaviours of animated objects. A curriculum in which traditional formalism is used only to solve abstract algebraic exercises may be considered as more distant from MoPiX formalism than when traditional formalism is used to express real world relations and behaviours. So, in contexts where the curriculum and pedagogy construct mathematics as applied and mathematical learning as experiential, MoPiX is less distant than in contexts where mathematics is considered as abstract and as an end in itself. The IOE experimentation In designing the classroom experimentation in London, the IOE team drew on the theoretical concerns discussed above as well as taking account of the educational context within which they were intervening. In accordance with the original conceptualisation of MoPiX as a means of addressing ideas about motion, we chose to work with students in their final year of pre-university studies (17 years old), for whom the study of elementary Newtonian mechanics formed a part of the mathematics curriculum. The high stakes nature of the examination system in England meant that the research team’s access to students necessitated making close connections to the existing curriculum and making these connections explicit to students and to teachers. The pedagogical plan was thus devised around constructs that could be identified within the standard curriculum, for example: straight-line motion, constant acceleration and acceleration as a force. The pedagogical plan and the organisation of the IOE teaching experiment were designed to enable students to communicate using pencil-and-paper-based representations involving conventional or informal notations or diagrams, using 'natural' language in face- 13 to-face speech and by sharing MoPiX objects, equations and models electronically. Some parts of the plan explicitly directed students’ attention to connections between different forms of representation, for example, making changes to values in given equations in order to observe and describe the effects of such symbolic changes on the motion of an animated object. At other times, students were given more open tasks in which they could choose which type of representation to use, for example, making an animated model of their own design, a task that in practice involved use of paper and pencil, a computer drawing package, gestures and talk as well as equations drawn from the MoPiX library, new equations formed by editing these and the moving objects produced on the MoPiX stage. In Morgan and Alshwaikh (2009) we present an example of the work of a pair of students on such an open task The multimodal social semiotic approach proposes an analytic focus on the ways in which different modes of representation function within teaching and learning interactions. The analytic method adopted by the IOE team thus identified: the ways in which each mode of representation was used; how students’ uses of the various modes of representation related to each other; and how the use of each mode of representation, both separately and in conjunction with other modes, contributed to the development of shared orientations to the task and to mathematical concepts (also see Morgan & Alshwaikh, 2009). The ETL experimentation The experimentation by the ETL team took place in a Secondary Vocational Education school in Athens. Eight 12th grade students (17 years old), studying mechanical engineering, worked in groups of two or three for 25 school hours. These students had not associated mathematics with engineering before and their experience reflected the lack of experiential learning activity characteristic of Greek schooling. They were enthusiastic to connect engineering with programming digital models. The researchers were not tightly restricted by specific curriculum or examination demands, so they designed activities which related to the engineering and mathematics curriculum while not necessarily tightly matching its expositional-theoretical nature. 14 A pivotal feature of the pedagogical plan was to give students what the ETL group call a 'half-baked microworld' and ask them to make changes to improve it (Kynigos, 2007). This is a digital artefact specially designed to be faulty or incomplete. The artefact incorporates an interesting idea but the point is for students to see sense in deconstructing it, in building on its parts, making changes and eventually constructing a new artefact, which may be distinctly different than the original one. In this case the artefact was called “The Juggler” (Kynigos, Psycharis, & Moustaki, 2010) and consisted of three interrelated objects: a red ball and two rackets with which the ball interacted. The ball was animated using equations to define its motion. Equations affecting the ball’s behaviour in relation to the rackets were especially created by the researchers with the use of the MoPiX formalism. The rackets were not animated, but it was possible to move them around using the mouse and thus make the ball ‘bounce’ on them, forcing it to move away in specific ways. The students were asked to execute the Juggler model, observe the animation generated and identify the conditions under which each object interacted with the others as well as the objects’ possible changes of behaviour because of these interactions. They were encouraged to discuss with their teammates how they would change the Juggler microworld and embed in it their own ideas regarding its behaviour. In the process of making changes the students were expected to deconstruct the existing model, linking the behaviours generated on the screen to the corresponding equations in order to reconstruct the microworld, employing strategies that would depict their ideas about the new model’s animated behaviours. During the experimentation process one researcher acted as a teacher since she had been a teacher in this school for several years and the other one as a co–researcher. During the activity itself, the researchers circulated among the teams, posing questions, encouraging students to explain clearly their ideas and strategies, asking for refinement and revision when appropriate and challenging students to express openly their thoughts and put into effect their ideas. At specific time points during the sessions the researchers orchestrated whole class discussions. For the ETL team, the representations are seen as artefacts which play the role of expressions of meanings. There are different possible ways to group these representations. 15 One is similar to the IOE approach i.e. with respect to the mode: formalism, graphical model, written text, spoken language. The other is with respect to the kind of artefact, for example a conditional equation linked with the respective model behaviour. A third is to group representations of a specific concept such as variable. In all cases, the constructionist framework focuses on reification, i.e. on how an artefact plays the role of an expressive object, how it is addressed, changed, discussed over and used. In analyzing the data, the ETL group first looked for instances where meanings stemming from the students’ interaction with the available formalism were expressed. The unit of analysis was the episode, defined as an extract of actions and interactions performed in a continuous period of time around a particular issue. The episodes which are the main means of presenting and discussing the data were selected (a) to have a particular and characteristic bearing on the students’ interaction with the available tools during which MoPiX formalism was used to construct mathematical meaning and (b) to represent clearly aspects of the reification processes emerging from this use (e.g. articulating variables and invariants within an equation and conceptualising the structure of an equation as a system of connections and relationships between its component parts). Examples of cross-analysis In this section we present two episodes, one from each of the two classroom experimentations and the analyses of these episodes provided by each of the two research teams. We then reflect on how these analyses differ and on the sources of these differences. As space is restricted, we provide a narrative account of each episode, including brief extracts of data that are particularly significant to our analyses. Episode 1 from the IOE experiment In the seventh session, students were introduced to the idea of acceleration applied to an object at an instant. They experimented with applying acceleration equations of the form Ax(ME,20)=3, observing the effect as a sudden change in direction. (Together with the equation Vx(ME,t+1)=Vx(ME,t)+Ax(ME,t), this increments the current velocity with a “kick”, applying an acceleration of 3 units in the horizontal direction when time is 20). Students were then posed the task of using such acceleration in order to draw a square. In an earlier 16 session students had worked on the outwardly similar task of drawing shapes (not including a square) by making changes in velocity. It was here that Roniv decided to start. Rather than using acceleration, he first used velocity equations to turn the corners of his square then started the task of drawing a square using acceleration equations. After some initial hesitation he created his object, assigned it a basic set of motion equations and, after a short period of trial and improvement using strategies such as changing the signs or swapping the values of Vx and/or Vy, found the necessary equations to turn the first corner of the square. He then completed the other corners of this square efficiently and accurately. Ron’s initial systematic trial and improvement strategy of changing the sign or swapping the values of the new velocity worked well in this case because of the nature of the relationship between horizontal and vertical components of velocities of perpendicular motions. On completing the task, his growing confidence was apparent as he explained spontaneously to his partner how to make an object turn right-angled corners. “ When you want it to turn you got to say at 20, or whatever you want, Vy equals zero, Vx equals three, whatever what happened, at 40, Vx equals zero, Vy equals minus three, at … “ He then started the task of drawing a square using acceleration equations. As he did this, he kept his model of a square formed by using changes in velocity on the screen and constructed his second model next to it, running both simultaneously and comparing the results at each stage. After creating the basic motion of the new object without hesitation, Ron then seemed to run into difficulties. As he tried to turn his first corner using trial and improvement as before, the change sign/swap values strategy no longer worked. He turned to alternative strategies such as doubling and trying extreme large and small values of acceleration. These strategies focused only on the values of the acceleration and his exploratory attempts appeared to take no account of the desired values of the velocity. After 11 minutes and 14 trials he succeeded in finding the values of acceleration needed to turn the first corner. Having 17 achieved this, he proceeded to turn the other corners successfully and relatively efficiently, having to make only minor corrections. When he came to the final corner, wishing to make the object stop, he encountered new difficulty as the pattern of changes of sign and values that was successful in turning corners was not useful for coming to a stop. At this point he flipped over the two models and examined the equations used in each case, apparently comparing the values of velocity and of acceleration at each of the corners. With significant pauses for thought, he succeeded in adding correct acceleration equations without further trials. Finally, having completed a correct model, he spent time inspecting the equations of the original model built using changes in velocity, pointing to the various values of velocity as if calculating what acceleration would be needed to achieve the same effect. Table 1 presents a comparison of Ron’s processes as he attempted the two tasks. ---- insert Table 1 about here ---Initial analysis from the IOE perspective Ron’s activity on this task is characterised by alternation between working with MoPiX formalism and running the animated model. The interaction between these two modes of representation is fundamental to his developing strategy. Ron’s earlier experience with MoPiX enabled efficient association of change of direction of motion with change in values of horizontal and vertical components of velocity. Two representational features of MoPiX seem to play an important role in this initial activity. The connectivity between MoPiX formalism and the movement of a graphical object enables a trial and improvement approach. Secondly, this approach works well because the symbolic language of MoPiX embodies the separation of velocities into horizontal and vertical components. By keeping his model of a square drawn using changes in velocity on the screen while constructing his second square using changes in acceleration, Ron’s behaviour seems to construe the two tasks as parallel, running both simultaneously and comparing the results at each stage. In the initial stages of the second task, however, he only compared the visual output of the animation, not the symbolic structure. Instead, he re-used his trial and improvement strategy, making use of the connectivity between formalism and graphics 18 within the second model but not between the two models. Unfortunately, in the case of acceleration, the value needed to produce a given velocity is dependent on current velocity rather than on the previous acceleration. After an extended period of trialling, his eventual success in finding the value of acceleration needed to turn the first corner enabled him to turn subsequent corners, presumably by following a numerical pattern, as he still did not appear to refer back to the desired values of velocity. This numerical pattern was not, however, useful when faced with the task of making the object stop at the final corner of the square. At this stage he turned to a comparison between the two models within the symbolic mode, flipping over both models and examining the equations used in each case. Engagement with the symbolic mode in MoPiX and interaction between this and the animation mode enabled him to complete the task successfully. His final period of inspection of the sets of equations for both objects, pointing in turn to the velocity equations used at each corner of the original model, suggests a move towards a focus on acceleration as change in velocity. Considering the relationships between the available representations and Ron’s activity, it appears that the congruence between simple numerical patterns in the values for velocity used in the formalism and perpendicular motions in the animated graphics enabled successful solution of the problem of constructing a square through using the number patterns. The lack of congruence between similar patterns in the values for acceleration and the desired motions, especially when bringing the model to a halt, demanded that Ron engaged in a different way with the formalism. Rather than focusing simply on the values of the variable to be changed, he had to make connections within the formalism between the values of velocity and of acceleration. Initial analysis from the ETL perspective Initially Ron attributed to his object ready-made equations that he found in the Equations Library classified under the “Horizontal” and “Vertical Motion Equations” categories. As he had already gained familiarity with the equations of those two categories and the meaning their symbols conveyed, Ron carefully selected only the equations that would assist him in drawing a shape and disregarded others. Having worked before with shape drawing using motion equations, Ron chose to bring to this task a strategy that he had previously followed 19 and that had proved successful. Thus, although he initially attributed to his object an acceleration equation, he preferred to investigate the role of the velocity equations -instead of acceleration equations- in drawing a square, which seemed to be consistent with what he had achieved up to that point. Having identified the meaning the symbols in the velocity equations conveyed and having particularly articulated an understanding regarding the variable of time and its specific role in the equations, Ron performed a series of changes not only on the right part of the equation, substituting one numerical value for another, but also on the left part of the equation, substituting the variable of time to specific arithmetic values. The continuous changes in the values as part of his experimentations with the velocity equations were not confined to substituting one arithmetic value for another but also involved sign changes to signify changes in the object’s direction. Ron’s initial systematic trial and improvement strategy of changing the sign or swapping the values of the new velocity worked well also because he had deep structure access to the symbolic facet of the model animated on the screen. In the process of debugging his model, Ron pressed the “Play” button to observe the animation generated and flipped his object to identify the equation responsible for the buggy behaviour several times, developing in the way meaningful connections between the mathematical formalism and the graphical/visual representation of the model. Specifying each time which equations needed to be fixed, Ron performed a series of changes editing the symbols of the velocity equations. Mentioning to his partner that he could use “20 or whatever you want” as the time point at which changes to the values of velocities should be made so as to change the object’s direction, Ron seems to have reached a higher level of abstraction as he appears to have identified “20” not as a fixed arithmetic value necessary in drawing any square but as a value that could be of the user’s choice. Ron used the model he had developed before as a starting point to go further with his experimentations with the acceleration equations. Thus, he initially attributed to his new object the equations he used to make the first object move upwards and draw one of the square’s sides bringing in once again strategies that he had successfully employed before. 20 As he had already created a model in which he used the velocity as the varying quantity inducing changes to the object’s direction, Ron focused on producing a new model having the exact same effect to the object’s direction, using this time the acceleration as the varying quantity instead of the velocity. The strategies he selected to use in this case also seemed to differentiate. In order to produce the first turn, Ron made several changes to the arithmetic value on the right side of the x and y acceleration equations. Nevertheless, these changes seemed to be coherent as he moved from doubling the value of the acceleration he had previously attributed to his object to giving extremely large and small values, observing in each case the animation generated. At that point Ron didn’t seem to have developed concrete links between the changes in acceleration and the changes in direction. The fact however that any actions he performed to the model’s symbolic facet (e.g. editing/modifying or at several times inserting/removing acceleration equations) produced a direct change to the visual result generated on the Stage, gave Ron the opportunity to gradually move to a more solid conceptualization of the mapping between direction and acceleration and to continue his construction having identified a pattern of changes to be made so as to make the object turn. Coming to the final corner, Ron seemed to have realised that the pattern he had previously identified and successfully used wouldn’t make his object come to a stop. Thus, instead of making any attempt to attribute the values 3 or -3 to the x and y accelerations as he had before, he decided to explore the potential of attributing to both accelerations the value -6. At this point, Ron seemed not to have identified exactly the way in which changes in the acceleration equations affected the velocity of the object (so as to make the necessary changes in the acceleration values and cause the object stop at a specific time point). In this case the deep structure access the user has in the MoPiX environment was again proven to be useful as Ron flipped both his objects to inspect the symbolic facet of the two models. Recognizing an equivalence between these two models, Ron seemed to be calculating at his second model the values of the X and Y velocities for each time instance (through the equations Vx(ME,t)=Vx(ME,t–1)+Ax(ME,t) and Vy(ME,t)=Vy(ME,t–1)+Ay(ME,t)) and compare them to the ones that appeared on his first model in the form of “V = an arithmetic value”. 21 Initially Ron seemed to be attempting to make connections between a varying quantity (the velocity in the first case and the acceleration in the second) and the changes in direction to be produced so as to make his object turn. He started inserting and changing arithmetic values in the velocity and acceleration equations and each time started the animation to observe the graphical effect of his actions. The deep structure access and the linked representations gave Ron the opportunity to develop an understanding between the changes in direction (the visual effect) and the modifications made to the acceleration and velocity equations (the manipulations performed using the mathematical formalism). However, during the last part of his experimentations with the acceleration equations, Ron seemed to develop an understanding regarding the relationship between the two varying quantities (i.e. the velocity and the acceleration) in drawing the squares. Up to that point, he didn’t seem to have made any connections between velocity and acceleration as in order to construct the first model he merely manipulated and modified velocity equations, while in order to construct the second one, he solely used acceleration equations. Any modifications made to each one of them were regarded in isolation. Flipping the two objects, the symbolic facets of the two models were put next to one other. Needing to calculate the velocity at each time instance for the second model and match the values calculated to the ones that appeared in the first one, Ron came to use the equations Vx(ME,t)=Vx(ME,t–1)+Ax(ME,t)” and Vy(ME,t)=Vy(ME,t–1)+Ay(ME,t) which describe the relation between the acceleration and the velocity at each time instance. Reflecting on the two analyses Before turning to consider theoretical differences reflected in the analyses, it is worth noting that the relationship of each team to the research context affected their analytic focus. The IOE team had been involved in designing and teaching lessons with a specific curricular focus. Their interest in analysing the episode, while primarily concerned with the ways the student made use of the multiple forms of representation, was also influenced towards considering the ways in which the student’s activity within the set task may have contributed towards the curricular goals envisaged in the task design (i.e. operating with acceleration as change in velocity). ETL chose not to address this curricular focus in their 22 analysis, rather making links to the key issue addressed in their own teaching experiment: the way symbolic formalism functioned as a resource in the problem solving process. In particular, the IOE analysis noted that the separation of horizontal and vertical components of motion in the MoPiX symbolic system appeared significant to the solution process. This separation was interpreted as enabling a match between the student’s pattern of positive and negative trials and the values of velocity required for perpendicular motion - a match which is no longer valid as the student proceeds to deal with acceleration, hence necessitating other strategies in order to achieve a successful solution. With its close connection to the specific curricular aims of the task, this representational aspect of MoPiX did not form part of the ETL analysis. Both analyses focus on the ways in which particular characteristics of the MoPiX environment appeared to affect the student’s behaviour and his pathway to successful completion of the task. For both teams, the connectivity between symbolic and animated graphic modes is identified as significant to the solution process and of interest theoretically. From the IOE perspective, this connectivity is of interest because of the additional meaning potential it affords, enabling the various systems of representation to be used both singly and in combination to construe mathematical meanings. The initial approach to the task was identified as “trial and improvement”. Although this phase of activity suggests that the student has a focus on pattern making rather than on relationships between the components of motion, repeated movement between symbolic and graphic modes combined with manipulation of the symbolic formalism also construes a causal relationship between the formalism and resultant graphic behaviour. ETL’s analysis also noted incidents in which the student, after starting and observing the animation, flipped the object to look for the equations that needed to be fixed so as to produce the desired visual effect. From their perspective, this behaviour is interpreted as evidence that the student was developing meaningful connections between the mathematical formalism and the graphical/visual representation of the model. 23 Another aspect of MoPiX considered important by the ETL team is what they term the “deep structure access” that the symbolic mode provides to the way objects behave. In the final part of this episode, flipping objects and putting side by side the symbolic facets of two equivalent models allowed the student to inspect and compare the equations comprising these models, using in this way the mathematical formalism as a means to develop an understanding of the relationship between the specific varying quantities appearing in both models. The IOE team also found the final part of the episode of interest. However, rather than interpreting this in terms of the student’s developing understanding, the inspection of the equations of the two models, accompanied by gestures indicating focus of attention, is of interest because it construes a connection between velocity and acceleration that was not apparent at earlier stages of the episode. Episode 2 from the ETL experimentation In the episode we consider here, a pair of students had inserted a new object, an ellipse, into the “Juggler” microworld and wanted to modify the behaviour of the moving ball so that it would change its colour according to whether it was higher or lower than the ellipse: S1 What I want to happen is that: when the ball is above the ellipse to become red and when it is below the ellipse to become green. I don’t care about when it hits [the ground]. Can we do this? S1’s partner related this conceptualisation of the desired effect to other effects familiar from their previous experience with the microworld: S2 You have to define something. How did you define the plane which is the ground? How did you define that on the right side there is a wall and that you can’t go beyond this wall? [The “ground” and the” wall” are elements of already existing equations that the students had used]. This need for definition was then related to the XY coordinate system: S1 This. The: “I am below now”. How will we write this? S2 Using the Y. Using the Υ. The Y. That is: when its Υ is 401, it is red. When the Y is something less than 400, it’s green! The students started to develop a new equation to express this behaviour in the Editor. As there was no in-built MoPiX symbol to express the idea of an object becoming green under 24 certain conditions, they created a new symbol gineprasino (i.e. become green in Greek), giving it the standard format of a MoPiX variable, varying over time t. The first version of their equation was developed as: gineprasino(ME,t)=y(ME,t)≤274 (1) As this equation did not achieve the desired effect, the students decided to construct another equation in which they attempted to integrate the gineprasino variable. They used the structure of an equation (provided in the MoPiX library) that they had already used: Vx(ΜΕ,t)= (not(amIHittingASide(ΜΕ,t–1))×(Vx(ΜΕ,t–1)+Ax(ΜΕ,t–1))+(amIHittingASide(ΜΕ,t–1))×(Vx(ΜΕ,t–1)×–1) (2) which defines how the velocity of an object changes, including a change of direction if it hits an edge of the MoPiX screen. This equation incorporates use of the variable amIHittingASide(ΜΕ,t), taken from the MoPiX library and defined as: amIHittingASide(ME,t)=(x(ME,t)≤ 0 or x(ME,t)799) and Vx(ME,t)≠0 (3) The students appeared to recognise a similarity between changing velocity under a given condition, as in (2), and changing colour under a given condition. They also attributed a similar role to the variables amIHittingASide and gineprasino, each of which identifies the condition under which the desired change is to take place. They thus duplicated the structure of (2), eliminating its specific content and using it as a template to define what would happen to the ball’s colour when below the ellipse: greenColour(ME,t)=not(gineprasino(ME,t))×0 + gineprasino(ME,t)×100 (4) greenColour is an in-built MoPiX variable, already familiar to the students, that may take values from 0 to 100, controlling the saturation of green. Like the variable amIHittingASide, the variable gineprasino acts as a truth function, taking values of 0 or 1 according to the current value of the y-coordinate of the object. Equation (4), applied to the ball object, thus assigns 100% green saturated colour to the ball when its y-coordinate is 274 or less (i.e. below the fixed position of the ellipse) and 0% green when it is above the ellipse (see Figure 2). 25 ---- insert Figure 2 about here ---Initial analysis from the ETL perspective In line with the analytical framework discussed before, the ETL group looked in this episode for events that indicate qualitative changes in the ways the students used the formal equations register. In their attempts to insert another object whose behaviour was related conditionally to the first object and to a fixed parameter in the geometrical plane (the y value), there were several events in which the students reified the equations as expressions through their interaction with the available tools. These events suggest that the students were able to develop insights into the consequences of the equations’ formalism on the behaviour of the two objects as well as to cope effectively with structural aspects of the equations. While building equation (1) the students thought to create a variable and to give it a name corresponding semantically to the variable's function (i.e. the gineprasino - become green variable). They also related the symbols with a mathematical system (i.e. the x-y coordinate system) and manipulated variables, numerical values, equals and inequality symbols. Surprisingly, in attempting to link the behaviour of the ball to its position relative to the ellipse, the way in which they used the y-coordinate concept for each object was distinct. The ball’s y-coordinate was expressed in terms of a quantity varying over time (y(ME,t)), while the ellipse’s y-coordinate was expressed in terms of the constant arithmetic value corresponding to the object’s position at that time on the Stage (i.e. 274). In building the second equation, the students’ meanings seemed to evolve by including a view of equations as objects, i.e. as higher order representational units. First, the students extracted mathematical meaning from an equation which as a whole seemed to describe a behaviour similar to the one they wished to attribute to their own object. Conceptualizing a mapping between the idea “the ball should change its velocity when it hits one of the Stage’s sides” and the idea “the ball should change its colour when it is situated below the ellipse”, the students used the structure of equation (2) but inserted new terms in order to define a completely novel behaviour for their object. This constitutes a clear indication that the students were able to relate the MoPiX equation they were constructing with an existing equation and to recognise mutual connections between those two structures. Thus, 26 students appeared to recognise the existence of structures external to the symbols themselves and use them as landmarks to navigate the construction process to produce equation (4). The manipulation of the terms of the equation reveals further their developing structural approach to equations. Inserting the gineprasino variable and providing it with new forms (i.e. not(gineprasino)), the students seem to have conceptualised equation (2) as an object and used it as a means to encode meaning and structure in equation (4). From the ETL perspective, this reflects a kind of mathematical thinking that relates to the development of a good algebraic structural sense accompanied with the acquisition of a functional outlook to equations as objects, which is considered to be crucial to relational understanding. Initial analysis from the IOE perspective As before, the IOE analysis focuses on relationships between the various modes of representation and the students’ activity. In this case, the episode involves movement between everyday language and the formalism of mathematical symbolic systems and MoPiX equations. S1 first uses everyday language to describe the goal of the activity. By the end of the initial discussion, this goal has been reformulated in terms of the XY coordinate system. We suggest that some representational characteristics of the MoPiX environment play an important role in this reformulation. In particular, there are a number of terms within the MoPiX symbolic language that may be considered “boundary” terms, reducing the distance of MoPiX from students’ previous experience: there is a convergence between MoPiX terms such as ground, side, and amIHittingASide and their use in everyday discourse. The interdiscursivity of such boundary terms allows the meaning potential of one system to inform how the other system is understood. The creation of the new symbol gineprasino (become green) relates MoPiX language to the original everyday expression of the goal of the activity. This can be considered a new boundary term. The construction of equation (1) may be seen as a direct movement from the everyday formulation of the goal: “gineprasino(ME,t)=y(ME,t)≤274” is a very close translation of “When the Y is something less than 400, it’s green”. However, this similarity also highlights fundamental differences between the two semiotic systems, indicating a high degree of epistemological distance. Whereas in everyday language “become green” is associated with 27 change in colour, in MoPiX formalism it has no such association. As defined in equation (1), gineprasino is simply a variable that may take values of 0 or 1 depending on the ycoordinate of the position of the object. By using the structures of everyday language, the students’ first attempt is not successful. The surprise provided by the visual feedback from this first attempt seems to have prompted a reappraisal of their approach. It is also likely that it prompted an association with earlier experience (evident in data drawn from previous episodes) attempting to use the terms amIHittingASide or amIHittingGround, which have similar properties to gineprasino, that is: an ‘everyday language’ meaning; MoPiX variable taking values 1 or 0; no visible effect on MoPiX animation unless integrated into other equations. The initial exchange as the pair negotiated the task also seems key to making this association and deciding to use equation (2) as a template: S2 had immediately recognised the relevance of previous work with “the plane which is the ground”. As we are looking at a process of development of a solution over time, the IOE analytic approach tracks the connections between the semiotic resources used as the episode progresses, reconstructing a semiotic chain as a means of examining how the everyday description of the visual characteristics of the imagined solution is transformed into a set of MoPiX equations that will realise that solution. The chain is reconstructed by identifying at each step of the episode the source of the semiotic resources used by the students (cf. Carreira, Evans, Lerman, & Morgan, 2002). In this episode the sources identified include ‘everyday’ language (e.g. “the ball is above the ellipse”), mathematical language (e.g. “x, y coordinates”), MoPiX formalism (e.g. “gineprasino(ME,t)=y(ME,t)≤274”). We additionally identify what we have called ‘boundary terms’ such as ground which are both part of everyday language and components of pre-defined MoPiX terms. Such boundary terms seem important in the formation of the semiotic chain, as they are both meaningful in the everyday discourse and functional within the MoPiX environment. Indeed, we see the newly formed term gineprasino to serve as a boundary term that plays a linking role in the transformation of the students’ original vision into a functioning MoPiX model. 28 Reflecting on the two analyses Comparing the IOE analysis of this episode with that provided by the ETL team, we note that both teams highlight the students’ identification and exploitation of similarities between their current goal and previous MoPiX experience with equations including terms such as amIHittingGround. The IOE focus on links in a semiotic chain, however, leads to some different interpretations. In particular, the construction of the equation gineprasino(ME,t)=y(ME,t)≤274, seen as surprising in the ETL analysis because of the different forms of expression used for the y-coordinates of the ball and of the ellipse, is explained in the IOE analysis as a close translation of the students’ earlier everyday/ mathematical language expression “When the y is something less than 400, it’s green”. The IOE analysis sees structural similarities both between expressions in different semiotic systems and between expressions within the MoPiX system as playing crucial roles in enabling the students to move towards the solution of their problem. While the ETL analysis also lays importance on links between expressions within MoPiX, in particular the use of existing equations as templates for the construction of new ones, it additionally posits the use of conceptual similarities between existing and new equations. While not denying the possibility of such conceptual connections, the IOE approach does not address them. Reflections on the cross-analysis The analytic approaches taken by the two teams are not on the whole incompatible and yield interpretations of the data that have some similarities. For example, in analysing episode 1, both analyses consider interaction between the symbolic formalism of MoPiX and its graphical effects as critical to the problem solving process and identify the student’s final inspection of the two sets of equations of the two models as key to his making connections between velocity and acceleration. However, the two teams emphasise different aspects of student use of the representations and a significant difference may be identified in the two analyses in the ways in which the two teams treat the representations offered by MoPiX and the relationships between different systems of representation. For ETL, the symbolic formalism of MoPiX plays a particularly important role because of the way that it provides access to the ‘deep structure’ of the environment. Furthermore, the 29 analysis is connected with a pedagogical intentionality, focusing on the ways in which formalism, through its connections with the other representations and affordances for manipulation, may become meaningful to the students. While the IOE perspective does not deny the role symbolism may play in meaning making, it does not have a privileged role in the IOE analysis. Rather, the various systems of representation are considered of equal significance, the interest being in analysing what each brings, both individually and in combination, to the possibilities for meaning making and problem solving. This difference is highlighted in the interpretations of the equation gineprasino(ME,t)=y(ME,t)≤274 in episode 2. Whereas the ETL analysis focuses within the symbolism on the different ways in which the value of the y-coordinate is expressed, the IOE analysis attends to the relationship between the structure of the equation and that of the students’ everyday expression of their goal. Discussion of issues of representation raised by crossanalysis In this final section, we reflect on how the cross-analysis has highlighted and sharpened our awareness of similarities and differences in the ways the two theoretical perspectives deal with representation. We also consider how this awareness moves us forward in the search for integration of theoretical perspectives. The issue of connections between different modes of representation has been significant in the analyses by both teams. Not only is this issue widely recognised as one of the important characteristics of representations enabled by digital technologies but the use of and movement between multiple modes was also one of the principles underpinning the design of MoPiX. While the importance of connections between representations was a common assumption at the start, the cross-analysis has enabled us to identify differences in the ways that “connection” may be conceptualised. For both teams the significance lies not simply in the formal presence of connections embodied in the design of the software but in the ways in which students interact with the various modes of representation. From the constructionist perspective, the connections made by students between graphical/dynamic mode and symbolic mode closely parallel the connections embodied in the design of MoPiX. 30 By interacting (“tinkering”) with the digital environment, these connections become meaningful for students, enabling them to access the “deep structure” of the system. The connection between two modes of representation is thus at a systemic level: the system of animated graphics and the system of symbols can be mapped onto one another. This mapping may be considered an example of conversion between registers, argued by Duval (2006) to play an important cognitive role in development of mathematical concepts. In contrast, connections are considered more pragmatically from the multimodal social semiotic perspective, analysing the ways in which the potentialities of each mode are realised as they are used separately and together and the ways in which combinations of modalities are utilised at each moment. While congruencies between modes of representation may provide an explanation for some of the ways they are used, their differences are also significant and serve a function in enabling meanings to emerge during student activity. Rather than seeking for structural connections between systems of representation, the following of chains of signification seeks for associations between specific signs (especially boundary terms) and the contexts and domains of activity within which they may have been encountered. This entails a wider consideration of the various modes of representation available to students, not just those made available by the technological environment. For example, in analysing episode 2, the IOE analysis focuses on connections with representations in natural language as well as the graphical and formal symbolic representations in MoPiX. Analysis using this perspective also entails drawing on knowledge of the domains of social activity in which particular representations play a part in order to interpret students’ use of these representations and the connections they may be making. Whereas a theoretical perspective on representation can adopt a neutral position on the value of a particular conjunction of representations, from a point of view situated within mathematics education, there clearly must be value ascribed to students’ developing relationships with mathematics. As anticipated, the context in which the experimentations took place, including the curricular context and the relationship between researchers and the site of research, may be seen to play a role in shaping the focus of each team’s analysis. While the IOE’s theoretically informed focus on the roles and relationships of different 31 systems of representation is seen in the analysis of both episodes, it is also apparent that in analysing their own classroom experimentation (episode 1), the IOE analysis attends to the development of connections between velocity and acceleration as this was an important part of the didactic aim of the experimentation. For ETL, the relationship to the official curriculum was less critical and their main focus on the students’ use of formalism can be seen equally in both analyses. This highlights a difference at a fundamental level between the two theoretical perspectives: while multimodal social semiotics is concerned with understanding how each mode of representation functions in producing meanings, constructionism has a major concern with educational relevance. Thus the constructionist perspective addresses the question of whether a given form of representation serves as a facilitator or an obstacle to the generation of meanings that are consistent with those of mathematics. Researchers working with this perspective also seek to design representations for facilitation of particular types of meanings and may give primary importance to one representation over others. For example, in using MoPiX, mathematical formalism is placed in a driving role of creating graphical representations with the didactical intention to find ways in which formalism may become meaningful to students. Recently, educational researchers using multimodal social semiotics have also sought to develop a related theory of learning that addresses the issue of designing representations for meeting educational goals (Bezemer & Kress, 2008; Kress & Selander, 2012). It will be interesting to see how outcomes of this development of the scope of social semiotics into didactic design relate to those arising from a constructionist perspective. A further issue that has become apparent to both authors as we have constructed this article but which has been largely deferred until this point has been the different ways in which we use the term meaning. For both of us, students “make meaning” with or from the use and manipulation of representations in interaction with others in the social environment. Moreover, in many instances we find ourselves largely in agreement about the relationships between the ‘meanings’ thus made and the mathematical objects and structures involved. However, while the constructionist perspective is concerned with meaning as (an ultimately individual) cognitive phenomenon, for social semiotics meaning 32 is conceptualised as the establishment of shared orientations through communication in interaction between individuals – meaning is located in the interaction rather than acquired by the individual. This difference reflects a fundamental difference in the object of the two theoretical perspectives: constructionism may be characterised as a theory about cognition and its development while social semiotics is a theory about signs and the ways they function. Awareness of this difference in our theoretical objects helps us to understand differences in the focus of our analyses and alternative explanations of phenomena. However, it also suggests that, where our interpretations converge, for example in identifying the significance of Ron’s shifting attention between graphic and symbolic modes, there is potential for building a richer, multi-faceted understanding of the phenomenon. In conclusion, the use of cross-analysis study on data derived from cross-experimentation has helped us sharpen and highlight our awareness of aspects of representation and meaning. Through examining the use of these terms within the two theoretical perspectives, two aspects in particular, which had seemed very similar before the study, came to be distinguished more clearly. One was the way in which connections between representations were conceptualized by each approach, the kinds of value given to each connection and the prioritisation of educational relevance or of explanatory relevance. The other development was a more nuanced understanding of how our perspectives perceive “meaning”, which in the case of constructionism seemed to address the individual in social settings and give an emphasis to cognition, while multimodal social semiotics identified it in the semiotic interactions. Our experience points to the potential usefulness of crossanalysis as a tool to elicit such distinctions and to forge connections in approaches to representations and their uses in mathematics education. It further opens the floor for the production of other such tools in an attempt to contribute to the networking of theoretical frames, augmenting the ways in which they can be used to design, impact and understand educational practices in a diversity of contexts. 33 Notes i ReMath was co-funded by the European Commission FP6-IST4-26751. Related resources can be found at http://remath.cti.gr. ii MoPiX can be found at http://remath.cti.gr/ and will run in any browser with Flash. iii MoPix was designed to run on tablet computers in order to facilitate face-to-face communication among students as well as the sharing of digital models on-line. iv Student names used here are all pseudonyms. References Ainsworth, S. E., Bibby, P. A., & Wood, D. J. (1997). Information technology and multiple representations: new opportunities - new problems. Technology, Pedagogy and Education, 6(1), 93-105. Artigue, M., Cerulli, M., Haspekian, M., & Maracci, M. (2009). Connecting and integrating theoretical frames: The TELMA contribution. International Journal of Computers for Mathematical Learning, 14, 217-240. Bezemer, J. & Kress, G. (2008). Writing in multimodal texts: a spcial semiotic account of designs for learning. Written Communication, 25(2), 166-195. Borba, M. C. & Villarreal, M. E. (2006). Humans-with-media and the reorganization of mathematical thinking: Information and communication technologies, modelling, experimentation and visualization. New York: Springer. Bottino, R. M., & Kynigos, C. (2009). Mathematics education & digital technologies: Facing the challenge of networking European research teams. International Journal of Computers for Mathematical Learning, 14, 203-215. Carreira, S., Evans, J., Lerman, S., & Morgan, C. (2002). Mathematical thinking: Studying the notion of 'transfer'. In A. D. Cockburn & E. Nardi (Eds.), Proceedings of the 26th Conference of the International Group for the Psychology of Mathematics Education (Vol. 2, pp. 185-192). Norwich: School of Education and Professional Development, University of East Anglia. Cobb, P. (2000). From representations to symbolizing: introductory comments on semiotics and mathematical learning. In P. Cobb, E. Yackel & K. McClain (Eds.), Symbolizing and Communicating in Mathematics Classrooms: Perspectives on discourse, tools and instructional design (pp. 17-36). Mahwah, NJ: Lawrence Erlbaum Associates. Dreyfus, T. (1994). The role of cognitive tools in mathematics education. In R. Biehler (Ed.), Didactics of mathematics as a scientific discipline, pp.201-211, Dordrecht: Kluwer Duval, R. (1999). Representation, vision and visualization: Cognitive functions in mathematical thinking. Basic issues for learning Proceedings of the Annual Meeting 34 of the North American Chapter of the International Group for the Psychology of Mathematics Education (pp. 3-26). Cuernavaca, Morelos, Mexico. Duval, R. (2006). A cognitive analysis of problems of comprehension in the learning of mathematics. Educational Studies in Mathematics, 61(1 - 2), 103-131. Edwards, L. D. (1998). Embodying mathematics and science: Microworlds as representations. The Journal of Mathematical Behavior, 17(1), 53-78. Falcade, R., Laborde, C., & Mariotti, M. (2007). Approaching functions: Cabri tools as instruments of semiotic mediation. Educational Studies in Mathematics, 66(3), 317333. Font, V., Godino, J. D. & D’Amore, B. (2007). An onto-semiotic approach to representations in mathematics education. For the Learning of Mathematics, 27(2), 2-7. Goldin, G. A. (1998). Representational systems, learning, and problem solving in mathematics. The Journal of Mathematical Behavior, 17(2), 137-165. Halliday, M. A. K. (1978). Language as Social Semiotic: The Social Interpretation of Language and Meaning. London: Edward Arnold. Harel, G., & Papert, S. (Eds.). (1991). Constructionism. Norwood, NJ: Ablex. Hodge, R., & Kress, G. (1988). Social Semiotics. Cambridge: Polity Press. Janvier, C. (1987). Problems of Representation in the Teaching and Learning of Mathematics. Hillsdale, NJ: Lawrence Erlbaum Associates. Kafai, Y., & Resnick, M. (Eds.). (1996). Constructionism in Practice: Designing, thinking and learnign ina digital world. Mahwah, NJ: Lawrence Erlbaum Associates. Kaput, J. J. (1991). Notations and representations as mediators in constructive processes. In E. van Glasersfeld (Ed.) Radical constructivism in mathematics education, pp.53-74. Dordrecht; Kluwer Kress, G., & Selander, S. (2012). Multimodal design, learning and cultures of recognition. The Internet and Higher Education, 15(4), 265-268. Kress, G., & van Leeuwen, T. (2001). Multimodal Discourse: The modes and media of contemporary communication. London: Arnold. Kynigos, C. (2007). Half-baked microworlds as boundary objects in integrated design. Informatics in Education, 6(2), 335-359. Kynigos, C. (2012). Constructionism: theory of learning or theory of design? Proceedings of the 12th International Congress on Mathematics Education. Seoul, S. Korea. Kynigos, C., Psycharis, G., & Moustaki, F. (2010). Meanings generated while using algebraiclike formalism to construct and control animated models. International Journal for Technology in Mathematics Education, 17(1), 17-32. Morgan, C., & Alshwaikh, J. (2009). Mathematical activity in a multi-semiotic environment. Sixth Congress of the European Society for Research in Mathematics Education, Working Group 6 Language and Mathematics, 993-1002. Retrieved from http://www.inrp.fr/editions/cerme6 Morgan, C., Mariotti, M. A., & Maffei, L. (2009). Representation in computational environments: epistemological and social distance. International Journal of Computers for Mathematical Learning, 14(3), 241-263. Noss, R., & Hoyles, C. (1996). Windows on Mathematical Meanings: Learning Cultures and Computers. Dordrecht: Kluwer. O'Halloran, K. L. (2005). Mathematical Discourse: Language, symbolism and visual images. London: Continuum. 35 Radford, L. (2009). Why do gestures matter? Sensuous cognition and the palpability of mathematical meanings. Educational Studies in Mathematics, 70(2), 111-126 Strohecker, C., & Slaughter, A. (2000). Kits for learning and a kit for kitmaking. CHI '00 Extended Abstracts on Human Factors in Computing Systems, 149-150. Vergnaud, G. (1998). A comprehensive theory of representation for mathematics education. Journal of Mathematical Behaviour, 17(2), 167-181. Vérillon, P., & Rabardel, P. (1995). Cognition and artefacts: a contribution to the study of thought in relation to instrumented activity. European Journal of Psychology of Education, 10(1), 77-101. Yerushalmy, M. (2005). Functions of interactive visual representations in interactive mathematical textbooks. International Journal of Computers for Mathematics Learning, 10, 217-249. 36