Design research is a methodological paradigm, mainly qualitative, that is currently being intensely applied and developed in educational research. In this work we briefly describe this methodology and, within it, we focus our attention on a specific type of studies: teaching experiments. After describing the main characteristics of these studies, we present some conclusions that have been obtained in two teaching experiments developed by the authors. This information may contribute, directly or by promoting reflection and discussion, to the development of this methodology and to its application.