ADDIE is an instructional systems design (ISD) framework that many instructional designers and training developers use to develop courses. The name is an acronym for the five phases it defines for building training and performance support tools: Analysis Design Development Implementation Evaluation Most current ISD models are variations of the ADDIE process. Other models include the Dick and Carey and Kemp ISD models. Rapid prototyping is another common alternative. Instructional theories are important in instructional materials design. These include behaviorism, constructivism, social learning, and cognitivism. History Florida State University initially developed the ADDIE framework in 1975 to explain, “...the processes involved in the formulation of an instructional systems development (ISD) program for military interservice training that will adequately train individuals to do a particular job and which can also be applied to any interservice curriculum development activity.” The model originally contained several steps under its five original phases (analyze, design, develop, implement, and evaluate). The idea was to complete each phase before moving to the next. Subsequent practitioners revised the steps, and eventually the model became more dynamic and interactive than the original hierarchical version. By the mid-1980s, the version familiar today appeared. The origin of the label itself is obscure, but the underlying ISD concepts come from a model developed for the U.S. armed forces in the mid 1970s. As Branson (1978) recounts, the Center for Educational Technology at Florida State University worked with a branch of the U.S. Army to develop a model, which evolved into the Interservice Procedures for Instructional Systems Development (IPISD), intended for the Army, Navy, Air Force, and Marine Corps. Branson provides a graphic overview of the IPISD, which shows five top-level headings: analyze, design, develop, implement, and control. Virtually all subsequent historical reviews of ID reference this model but, notably, users do not refer to it by the ADDIC acronym. The authors and users refer only to IPISD. Hence, it is clearly not the source of the ADDIE acronym. Phases of ADDIE (Analysis, Design, Development, Implementation and Evaluation) Analysis phase The analysis phase clarifies the instructional problems and objectives, and identifies the learning environment and learner's existing knowledge and skills. Questions the analysis phase addresses include: Who are the learners and what are their characteristics? What is the desired new behavior? What types of learning constraints exist? What are the delivery options? What are the pedagogical considerations? What adult learning theory considerations apply?