The demonstration model (DEMON) uses a completely interactive computer implementation and operation; i.e., an analyst or planner enters the project structure to be studied via a prompting computer terminal and the results are printed or displayed during each computer run. Target groups might enter the system in a more or less steady flow; for example, a person might enter the system after arrest on drunk driving charges. He would then be assigned to either an experimental or control group, and his behavior would be tracked to calculate recidivism behavior following use of traditional sanctions or treatment methods being studied. Recidivism is modeled based on exponential times to future offenses. Statistical tests are made to determine treatment effects on future offenses. The volume describes 11 DEMON stage types that were used to examine an actual candidate project demonstration, provides an example of the modeling process, and discusses DEMON's examination of the candidate project demonstration. It is concluded that the model permits proposed projects to be analyzed readily for feasibility of budget, personnel, flow, and sampling requirements. Six tables and nine figures are given.