Book excerpt: Formative and design experiments represent a methodology uniquely suited for educational research in general and literacy research in particular. Providing a practical overview of this emerging and promising approach, the authors address the following questions: What is the origin of formative and design experiments and how do they compare to other approaches to investigating interventions in classrooms? How do you conceptualize, plan, conduct, and report formative and design experiments? What practical, ethical, and methodological issues might be encountered when using this approach? What is the current status and future potential of this approach?