Introduction by the book editors Part 1 Theoretical and empirical analyses of psychological processes in thinking and learning with external representations 1. Creative thinking and problem solving with depictive and descriptive representations Wolfgang Schnotz, Christiane Baadte, Andreas Mulle and Renate Rasch (University of Landau, Germany) 2. Instructional considerations in the use of external representations: the distinction between perceptually-based depictions and pictures that represent conceptual models Stella Vosniadou (University of Athens, Greece) 3. Critical thinking about biology during web page reading: tracking students' evaluation of sources and information through eye fixations Lucia Mason & Nicola Ariasi (University of Padua, Italy) 4. Representational fluency and flexibility in the domain of linear functions: A choice/no choice study Ana Acevedo Nistal, Wim van Dooren, Geraldine Clarebout, Jan Elen, & Lieven Verschaffel (University of Leuven, Belgium) 5. Representations and proof: the case of the Isis problem Brian Greer, Dirk De Bock, & Wim Van Dooren (1 San Diego State University 2 University of Leuven, Belgium) 6. Secondary school students' availability and activation of diagrammatic strategies for learning from texts Michael Schneider, Catrin Rode and Elsbeth Stern (Swiss Federal Institute of Technology of Zurich, Switzerland) Part 2 Development of representational tools and evaluation of their effects on student learning 7. Conceptual change in learning electricity: On the role of virtual and concrete external representations Tomi Jaakkola, Sami Nurmi & Erno Lehtinen (University of Turku, Finland) 8. Using static and dynamic visualisations to support the comprehension of complex dynamic phenomena in the natural sciences Peter Gerjets, Birgit Imhof , Tim Kuhl , Vanessa Pfeiffer, Katharina Scheiter, and Sven Gemballa (Knowledge Media Research Center, Tubingen, Germany) 9. The role of external representations in learning combinatorics and probability theory Bas Kolloffel, Tessa H. S. Eysink, and Ton de Jong (University of Twente, The Netherlands) 10. Symbolizing and the development of meaning in computer-supported algebra education Koeno Gravemeijer, Michiel Doorman, and Paul Drijvers (University of Utrecht, The Netherlands) 11. The "numbers are points on a line" analogy: Does it have an instructional value? Xenia Vamvakoussi, (University of Athens, Greece) 12. Use of external representations in science: prompting and reinforcing prior knowledge activation Sandra Wetzels, Liesbeth Kester, & Jeroen van Merrienboer (University of Heerlen, The Netherlands) 13. Visualization of argumentation as shared activity Gijsbert Erkens, Paul Kirschner &, Jeroen Janssen (University of Utrecht, The Netherlands)