Many training projects seek to obtain the maximum return from investment in computer based training (CBT) by adapting the training materials to all potential trainees in diverse nations and settings. Lesson prototyping, especially modeling of the interactivity between the trainee and the program, provides a means to confirm the effectiveness of the program before investments are made in preparing multi-cultural presentation materials. The interactivity model enables program designers to gather data on trainee interaction at the earliest possible stage of development. Data collected from trainee and expert interaction with the interactivity model is used to modify the structure of the presentation and insure that all training requirements have been addressed. Data collection from an interactivity model is particularly valuable in determining assistance requirements and cultural factors in the program structure early in the development process. This methodology may help to reduce overall training development costs and lead time.