NATO ASI Series Advanced Science Institutes Series A series presenting the results of activities sponsored by the NATO Science Committee, which aims at the dissemination of advanced scientific and technological knowledge, with a view to strengthening links between scientific communities. The Series is published by an international board of publishers in conjunction with the NATO Scientific Affairs Division A Life Sciences Plenum Publishing Corporation B Physics London and New York C Mathematical and Physical Sciences Kluwer Academic Publishers D Behavioural and Social Sciences Dordrecht, Boston and London E Applied Sciences F Computer and Systems Sciences Springer-Verlag G Ecological Sciences Berlin Heidelberg New York H Cell Biology London Paris Tokyo Hong Kong I Global Environmental Change Barcelona Budapest PARTNERSHIP SUB-SERIES 1. Disarmament Technologies Kluwer Academic Publishers 2. Environment Springer-Verlag 3. High Technology Kluwer Academic Publishers 4. 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[JpJrp Series F: Computer and Systems Sciences, Vol. 138 The ASI Series F Books Published as a Result of Activities of the Special Programme on ADVANCED EDUCATIONAL TECHNOLOGY This book contains the proceedings of a NATO Advanced Research Workshop held within the NATO Special Programme on Advanced Educational Technology, running under the auspices of the NATO Science Committee.The volumes published so far in the Special Programme are as follows (further details are given at the end of this volume): 67: Designing Hypermedia for Learning. 1990 76: Multimedia Interface Design in Education. 1992, 2nd corr. print 1994 78: Integrating Advanced Technology into Technology Education. 1991 80: Intelligent Tutoring Systems for Foreign Language Learning. 1992 81: Cognitive Tools for Learning. 1992 84: Computer-Based Learning Environments and Problem Solving. 1992 85: Adaptive Learning Environments: Foundations and Frontiers. 1992 86: Intelligent Learning Environments and Knowledge Acquisition in Physics. 1992 87: Cognitive Modelling and Interactive Environments in Language Learning. 1992 89: Mathematical Problem Solving and New Information Technologies. 1992 90: Collaborative Learning Through Computer Conferencing. 1992 91: New Directions for Intelligent Tutoring Systems. 1992 92: Hypermedia Courseware: Structures of Communication and Intelligent Help. 1992 93: Interactive Multimedia Learning Environments. 1992 95: Comprehensive System Design: A New Educational Technology. 1993 96: New Directions in Educational Technology. 1992 97: Advanced Models of Cognition for Medical Training and Practice. 1992 104: Instructional Models in Computer-Based Learning Environments. 1992 105: Designing Environments for Constructive Learning. 1993 107: Advanced Educational Technology for Mathematics and Science. 1993 109: Advanced Educational Technology in Technology Education. 1993 111: Cognitive Models and Intelligent Environments for Learning Programming. 1993 112: Item Banking: Interactive Testing and Self-Assessment. 1993 113: Interactive Learning Technology for the Deaf. 1993 115: Learning Electricity and Electronics with Advanced Educational Technology. 1993 116: Control Technology in Elementary Education. 1993 119: Automating Instructional Design, Development, and Delivery. 1993 121: Learning from Computers: Mathematics Education and Technology. 1993 122: Simulation-Based Experiential Learning. 1993 125: Student Modelling: The Key to Individualized Knowledge-Based Instruction. 1994 128: Computer Supported Collaborative Learning. 1995 129: Human-Machine Communication for Educational Systems Design. 1994 132: Design of Mathematical Modelling Courses for Engineering Education. 1994 133: Collaborative Dialogue Technologies in Distance Learning. 1994 135: Technology Education in School and Industry. 1994 137: Technology-Based Learning Environments. 1994 138: Exploiting Mental Imagery with Computers in Mathematics Education. 1995 140: Automating Instructional Design. 1995 141: Organizational Learning and Technological Change. 1995 142: Dialogue and Instruction. 1995 146: Computers and Exploratory Learning. 1995 Exploiting Mental Imagery with Computers in Mathematics Education Edited by Rosamund Sutherland Department of Mathematics, Statistics and Computing Institute of Education, University of London London WC1H0AL, UK John Mason Mathematics Faculty, The Open University Milton Keynes MK7 6AA, UK Springer Published in cooperation with NATO Scientific Affairs Division Proceedings of the NATO Advanced Research Workshop on Exploiting Mental Imagery with Computers in Mathematics Education, held at Eynsham Hall, Oxford, UK, May 20-25, 1993 CR Subject Classification (1991): K.3. I.3, J.2 ISBN 978-3-642-63350-8 ISBN 978-3-642-57771-0 (eBook) DOI 10.1007/978-3-642-57771-0 CIP data applied for This work is subject to copyright. All rights are reserved, whether the whole or part of the material is concerned, specifically the rights of translation, reprinting, reuse of illustrations, recitation, broadcast ing, reproduction on microfilms or in any other way, and storage in data banks. Duplication of this publication or parts thereof is permitted only under the provisions of the German Copyright Law of September 9, 1965, in its current version, and permission for use must always be obtained from Springer-Verlag. Violations are liable for prosecution under the German Copyright Law. © Springer-Verlag Berlin Heidelberg 1995 Typesetting: Camera-ready by authors Printed on acid-free paper SAP: 10084527 45/3142 - 5 4 3 2 1 0 Preface This book results from the NATO Advanced Research Workshop, Exploiting Mental Imagery with Computers in Mathematics Education, held at Eynsham Hall Oxford in May 1993. The advent of fast and sophisticated computer graphics has brought dynamic and interactive images under the control of professional mathe maticians and mathematics teachers at school and university. The workshop brought together researchers from a variety of disciplines, computer science, mathematics, mathematics education, psychology and design, in order to explore the ways in which images generally and computer generated images in particular can be exploited and developed. Throughout the workshop participants actively engaged in discussion of their collective research and also worked on their own use of mental imagery. Participants were involved in peer group reviewing of the conference papers and the chapters in this book represent the lively debate which was provoked by the conference. A number of central issues for further research emerged from the conference. One of these was the role of sketching in mathematical activity. There was general agreement that the sparseness of a sketch facilitates the creation, manipulation and transformation of visual images, but debate as to whether or not computer environments would be able to support this sketching process. The workshop drew attention to the need for research to investigate the characteristics and role of mathematical sketching on paper. It seems that competent mathematical students make use of a range of representations within this sketching process, but further research should be carried out on how student's use of multiple representations relates to their presentation within computer environments. The workshop was concerned with the educational implications of computer based imagery. There was agreement that students actively construct mental images and that the student's constructions will not necessarily be the same as those presented by the teacher or the computer. We became aware throughout the conference that some participants were more able than others to construct and manipulate mental images of mathematical objects, and that this ability cannot be separated from mathematical knowledge and previous experience. A number of presentations centred around the idea that geometry offers a privileged domain for an analysis of the dialectic process of conceptualisation and visualisation. But attention was also drawn to the fact that geometrical figures are VI Preface a special kind of image taking on a dual discursive and semiotic role. Imagery plays a role within all mathematical domains (for example algebra) and we must be cautious about generalising research results from one domain to another. We agreed about the potential of computer-based dynamic imagery which can be directly manipulated by students, because movement provides the opportunity for students to discover mathematical properties by attending to what is variable and what is invariant. The workshop highlighted the need for more research on how students appropriate and make use of these dynamic images. Throughout the conference there was debate about the relationship between mental imagery and spoken and written discourse. Some participants believed that it is not sufficient to build up, in the imagination, representations of mathematical objects and concepts, because mathematical objects (for example the natural numbers) are essentially discursive. We have organised the book into four parts. The authors in Part I are concerned with the role of the external imagery. In Part 2 the authors focus on the role of mental imagery in the teaching and learning of geometry. Authors in Part 3 develop the links between screen and mental imagery. Finally in Part 4 the authors focus on the ways in which students read and use imagery. We would like to thank the members of the organising committee, Nicolas Balacheff, Sandy Dawson and Maria Alessandra Mariotti for all their support in the planning of the conference. We are also very grateful to Lulu Healy and Stefano Pozzi for their energetic support throughout the conference. Finally the production of this book could not have been completed without the systematic endeavour of Magdalen Meade. January 1995 Rosamund Sutherland John Mason Contents Part 1. Emphasizing the External Imagery for diagrams 3 Tommy Dreyfus External representations in arithmetic problem solving 20 Giuliana Dettori and Enrica Lemut Visualisation in mathematics and graphical mediators: an experience with 11-12 year old pupils ................................................... 34 Angela Pesci Visual organisers for formal mathematics 52 David Tall Mediating mathematical action 71 Rosamund Sutherland Mathematical objects, representations, and imagery 82 Willibald D6rjler Part 2. Imagery in Support of Geometry 95 Images and concepts in geometrical reasoning 97 M. Alessandra Mariotti Between drawing and figure 117 Reinhard Holzl The functions of visualisation in learning geometry 125 Eric Love Geometrical pictures: kinds of representation and specific processings 142 Raymond Duval VIII Contents Part 3. Linking Screen and Mental Imagery 159 Overcoming physicality and the external present: cybernetic manipulatives 161 James J. Kaput On visual and symbolic representations ...................................................... 178 Luis E. Moreno A. and Ana Isabel Sacristan R. The dark side of the Moon .. ........ ........ ...... ........ .......... ...... ............ ............... 190 Richard Noss and Celia Hoyles Ruminations about dynamic imagery (and a strong plea for research) 202 E. Paul Goldenberg On designing screen images to generate mental images 225 Richard J. Phillips, John Gillespie, and Daniel Pead Learning as embodied action ........ ............ .......... ........ .......... ........ ............... 233 Stephen Campbell and A. J. (Sandy) Dawson Part 4. Employing Imagery 251 The importance of mental perception when creating research pictures 252 Monique Sicard and Jean-Alain Marek Random images on mental images 263 Mario Barra Imagery as a tool to assist the teaching of algebra 277 Dave Hewitt Mathematical screen metaphors 291 John Mason and Benedict Heal Exploiting mental imaging: reflections of an artist on a mathematical excursion ............ ................ .............................................. ....... ....... .............. 309 Stephen A.R. Scrivener Index 323 Part 1 Emphasising the External This part focuses on the ways in which external images and discourse interact with students' approaches to solving problems in mathematics. In the first chapter Tommy Dreyfus suggests that visual images contain strongly interpreted variations, arguing against the classical view of imagery as internalised perception. In contrast to Eric Love (Part 2) he maintains that the ability to transform mentally visual images can be enhanced by external visual support. He stresses that students have to learn to read mathematical diagrams, and suggests that there could be advantages in students constructing these diagrams for themselves and disadvantages in diagrams being automatically constructed by a computer. In school mathematics students are not encouraged to communicate with diagrams and a diagram does not usually count as an answer to a problem, and so, if we want students to use diagrams, their communciation function needs more emphasis. Dreyfus ends this chapter by discussing the potential importance of thinking with 'vague' images, a notion for which the term knodeling was coined during the conference. Giuliana Dettori and Enrica Lemut are concerned with the role of external representations in arithmetic problem solving. They stress that external represen tations become tools for dialogue both inter-personally and intra-personally and emphasise the link between external and internal representations. They agree with Tommy Dreyfus that students have to be taught how to represent mathematicsl problems, and discuss the differences between representing a resolution strategy and representing a computation strategy. They suggest that good problem solvers use representations which contain the germs of their resolution strategies. They also suggest that pupils can use external representations to support and unblock arithmetic problem solving processes. Angela Pesci also focuses on the use of external representations in arithmetic problem solving, in particular the use of arrow schemes in inverse problems. She maintains that these graphical images mediate, in the sense of Vygotsky, the cognitive activities needed to solve inverse arithmetic problems. Finally in this chapter Angela Pesci discusses some of the methodological issues involved in carrying out research in school settings. David Tall discusses his research with students who were training to be mathematics teachers. These students were presented with computer-based visual images in order to encourage them to visualise and verhalise advanced mathe- 2 Part 1 matical ideas. He discusses ways of displaying meaningful images of functions, which discriminate between rational and irrational numbers, and the relevance of these visual displays in developing a sense of continuity and discontinuity, differentiability and non-differentiability. He also discusses the weakness of using a finite computer screen to display images of objects for which infinity is an essential component. In the fifth chapter, Rosamund Sutherland considers the importance of external representations as mediators of mathematical problem solving and maintains that it is the "person acting with mediational means" which should be the focus of study. This allows for students to solve problems with a range of external visual and symbolic tools, and places value on these external productions as opposed to internal mental processing. All the authors of the preceding chapters, whilst focusing on external imagery, do not deny the role of mental imagery. Willibald Dorfler, on the other hand, maintains that there can be no mental imagery of abstract mathematical objects, for example the mathematical idea of even-ness. He stresses that mathematical objects are created by mathematical discourse and it is discourse which allows us to talk about these abstract objects and which constitutes the rules of how to talk about them. From this perspective a system of representations provides meaning for the mathematical discourse, but is qualitatively different from this discourse. Students have to become convinced about the sense of the mathematical discourse, and Dorfier suggests that representation systems can support this sense making.