This article introduces a research approach already in use in the Anglo-Saxon world for some twenty years. American, European and Asian researchers are showing growing interest for educational design research. A flexible process of analysis-design-evaluation-revision of the intervention together with a theoretical contribution characterise this approach. Iterative in essence, and rather theory building than theory testing oriented, its methodology focuses on the use of mixed methods and design languages. The necessity of anchoring the design in appropriate theories and the engineering based approach - used to create the mediating artifact - may explain why educational design research is appreciated in the field of educational technology.