This volume of the 27th International Group for the Psychology of Mathematics Education Conference presents papers from: plenary panels; research forums; working sessions; discussion groups; short oral communications; and poster sessions from the meeting. Plenary lectures included: (1) Studying and Capturing the Complexity of Practice: The Case of the Dance of Agency (Jo Boaler); (2) Voyaging from Theory to Practice in Teaching and Learning: A View from Hawaii (Barbara Dougherty and Joseph Zilliox); (3) The Dialectics between Theory and Practice: Theoretical Issues and Practice Aspects from an Early Algebra Project (Nicolina Malara); and (4) Probing Students' Understanding of Variables through Cognitive Conflict: Is the Concept of a Variable So Difficult for Students to Understand (Toshiakaira Fujii). Plenary Panel, Teachers Who Navigate between Their Research and Their Practice, included: (1) The Teacher/Researcher Roles (Jarmila Novotna); (2) A Moment in Time, Twisted between History and Practice (Agatha Lebethe); (3) Navigating between Research and Practice: Finding My Own Way (Vicki Zack); and (4) With Less Do More (Gershon Rosen). The first research forum, "Perceptuo-Motor Activity and Imagination in Mathematics Learning," included: (1) Three Conjectures Concerning the Relationship between Body Activity and Understanding Mathematics (Ricardo Nemiroskvy); (2) Approaching Algebra through a Motion Experiences (Ornella Robutti and Fernando Arzarello); (3) Incorporating Experiences of Motion into a Calculus Classroom (Marty Schnepp and Daniel Chazan); (4) Sensors, Body, Technology and Multiple Representations (Marcelo Borba and Nilce Scheffer); and (5) Becoming Friends with Acceleration: The Role of Tools and Bodily Activity in Mathematical Learning (Chris Rasmussen and Ricardo Nemiroskvy). The second research forum, "Equity, Mathematics Learning and Technology," included: (1) Equity, Mathematics Learning and Computers: Who Gets a Fair Deal in Australian SecondarySchools? (Helen J. Forgasz); (2) Mathematical Literacy in Higher Education: Attracting Women to Engineering Professions by Using ICT (Christine Keitel); (3) Availability and (Non-) Use of Technology in and for Mathematics Education in Poor Schools in South Africa (Mamokgethi Setati); (4) Equity, Mathematics Learning and Technology--Introduction (Gilah C. Leder); (5) Feminist Frameworks for Researching Mathematics (Gabriele Kaiser); (6) Windows on Practice: Investigating Equity in Technology Based Mathematics Classrooms (Colleen Vale); and (7) Some Issues Facing Work for Equity in Mathematics Education (Walter G. Secada). Research Report, Facilitating the Teaching of Space Mathematics: An Evaluation (Kay Diane Owens) concludes this volume of the 27th proceedings. Information relating to: working sessions; discussion groups; short oral communications; and poster sessions is also included. (Individual papers contain references.) [For 2002 Proceedings Volumes 1-4, see ED476065.]