Résumé en anglais

The C–K theory is a recent theory of reasoning in design. Despite many practical applications, the theory has not yet been operationalized in the form of a computational design tool. In this paper, we argue that, in order to build such tools, a third space—an environment space E—must be introduced to the theory. Therefore, we extend the C–K design theory, using ideas and principles from situated cognition. As we discuss, the new version provides a theoretical background for building personal design assistants—creative and adaptive design tools.