by the availability of a position opening. It is important to note that the philosophy of the military services is to recruit motivated individuals with an appropriate ability level—the skill and the knowledge needed for each military job is then developed through military training.

Studies examining how well the ASVAB subset scores predict job performance have shown only a weak relationship (National Research Council, 1991). More recently, the level of prediction from the ASVAB to job performance has been further reduced by the fact that, although jobs are changing with the introduction of technology, the old job descriptions remain in place.

Training prepares personnel to perform the tasks necessary to meet the mission or goals and objectives of the system. Development of training requirements, methods, curricula, and training system design are important parts of the overall system design process. The length and intensity of training depends on the background, ability levels, and learning styles of the personnel in the training class; the complexity of the system; and the level of skill and knowledge needed to ensure the desired level of performance speed and accuracy. Some training is designed for individual task performance; some for team or unit-level performance. An important input to effective training is a task analysis that identifies the skills and knowledge needed for acceptable performance—this analysis requires updating as the system configuration changes or as new automation is introduced. Although there may be some task analysis requirements that are unique to the training domain, the methods for creating this task analysis are substantially the same as those used for other system development purposes discussed in this report. Inadequate training can result when work and task descriptions are outdated. Training deficiencies may also result from failure to allocate the necessary training time and budget, lack of flexible training schedules needed to meet learning requirements, and lack of useful proficiency criteria.

Manpower, personnel, and system design decisions should take into account the level of training needed and the feasibility of delivering that training in the allowable time frame.

The private or commercial sector is more difficult to characterize because of the wide variety of systems and products, of the differences in approaches to human-system design, the central role of marketing, and because in the commercial product environment projects are more likely to be cancelled if milestones are not met in the early stages of the development process. Companies generally develop products for use by other companies, groups, or individuals. Some products require extensive training, and