The ADDIE model is a five-phase instructional design model for developing training programs consisting of Analysis, Design, Development, Implementation, and Evaluation. Each phase has outcomes that inform the next phase. There are over 100 variations of the generic ADDIE model. Gagne's Nine Events of Instruction outlines nine instructional events to consider when designing lessons: gain attention, state objectives, stimulate recall, present content, provide guidance, elicit performance, provide feedback, assess performance, and enhance retention and transfer. Storyboarding is used in instructional design to plan lessons by considering what content, who is involved, how it will be delivered, where, and when.