Vol. 27 Num. 2 (2007) Vicenc Font , Juan D. Godino , Bruno D'Amore An onto-semiotic approach to representations in mathematics education2 Beth Herbel-Eisenmann , David Wagner A framework for uncovering the way a textbook may position the mathematics learner8 Rina Zazkis , Roza Leikin Generating examples: From pedagogical tool to a research tool15 Fulvia Furinghetti , Francesca Morselli For whom the frog jumps: the case of a good problem solver22 Pessia Tsamir Should more than one theoretical approach be used for analyzing students' errors? The case of areas, volumes and integration28 Nick Pratt , Peter Kelly Mapping mathematical communities: Classrooms, research communities and masterclass hybrids34 Tony Cotton What is it like to be here? A methodology40 Maria Trigueros , Maria Dolores Lozano Developing resources for teaching and learning mathematics with digital technologies: an enactive approach45