Bulding upon the foundation of instrucitonal design practice, we now turn to the sources of knowledge instructional designers rely on to carry out their practice. Instructional design uses both academic sources of knowledge as well as practical forms of know-how. Both are needed to successfully solve instructional design problems or address instructional design challenges. Some design knowlege is personal to the designer, while other forms are codified into processes or other techniques. 

After reviewing some of the explicit and tacit sources of design knowledge upon which instructional designers rely, we then address instructional design processes as forms of design knowledge. We also include chapters that summarize the practical knowledge invovled in designing different kinds of instructional activities. We conclude with knowledge that is useful for designers to develop and sustain the working relationships they need for the challenges they address. Each of these four subsections contains between 3 - 8 chapters.