the goal of this presentation is to explore the multiple definitions of design research in education, and particularly in mathematics education. in doing so, i revisit components of brown, a. l. (1992)*, which highlight the issues for warrant. i argue that as yet her concerns have gone relatively unheeded by the education research community. i point to the need for mixed methodologies in support of design based insights and develop a validity framework that is inclusive of design adaptation issues. * design experiments: theoretical and methodological challenges in creating complex interventions in classroom settings. journal of the learning sciences, 2, 141-178.brown, a. l. (1992)