The ADDIE model is one of many course development methods used by instructional designers and training developers.  ADDIE is the accromyn for the five phases—Analysis, Design, Development, Implementation, and Evaluation.  The ADDIE method represents a responsive and flexible guideline for building effective training and performance support courses.

Sometimes, the ADDIE model is referred to as an Instructional Systems Design (ISD) model. Many instructional design models are variations of the ADDIE model; other models include the Dick & Carey and Kemp ISD models. The ADDIE model is one of the few models that accepts the use of rapid prototyping. This is the idea of receiving continual feedback while instructional materials are being developed. This model attempts to save time and money by catching problems while they are still easy to fix.

Instructional theories also play an important role in the design of instructional materials. Theories such as behaviorism, constructivism, social learning and cognitivism help shape and define the outcome of instructional materials.