This chapter discusses the foundations of instructional development and analyzes the development of various models, paradigms, archetypes, and themata used to describe instructional development. Two key strands in the literature of instructional development--instructional efficiency ("doing the right things") and instructional effectiveness ("doing the things right")--are described. Objective and subjective paradigms are then considered, as well as three archetypes of instructional development: the audiovisual, engineering, and problem-solving archetypes. In conclusion, it is argued that instructional development should be viewed not as a process, but as a set of criteria to which the technologies of the field must contribute. Two figures are included. (30 references) (Author/EW)