The field of Design Theory and Methodology has a rich collection of research results that has been taught at educational institutions as well as applied to design practices. First, this keynote paper describes some methods to classify them. It then illustrates individual theories and methodologies focusing on industrial and educational use. Theories and methodologies that are found most practically useful are ‘‘math-based methods’’, ‘‘methodologies to achieve concrete design goals,’’ and ‘‘process methodologies’’, while at educational institutes in addition to these, traditional design methodologies are also taught. The paper discusses this gap between practical and educational usages.