'Spiral curriculum' may be a term that you haven't heard before, but you certainly have learned from such a curriculum in your own student life. This lesson will provide a definition of spiral curriculum as well as some examples of the educational tool in action.
An Instructional Designer should conduct a needs research and analyze the needs of the targeted group. They have to determine whether these needs can be fulfilled by learning; and exactly how. They write they learning objectives and conduct research to see what the outcomes are.
It is an Instructional Systems Design (ISD) model. Most of the current instructional design models are spin-offs or variations of the ADDIE model; other models include the Dick & Carey and Kemp ISD models. One commonly accepted improvement to this model is the use of rapid prototyping.