Introduction -- Part I: Theoretical Aspects -- Theoretical issues related to designing and developing Teaching-Learning Sequences, Psillos, D., Kariotoglou, P. -- Pragmatic Design-based research - Designing as a shared activity of teachers and researches, Juuti, K., Lavonen, J. -- Participatory Approaches to Curriculum Design within a design-research perspective., Couso, D. -- Part II: Aspects …