The development of information systems using an engineering approach employing both traditional programming techniques and nonprocedural languages is described. A fourth generation application tool is used to develop a prototype system that is revised and expanded as the user clarifies individual requirements. When fully defined, a combination of cost-effective techniques is used to develop the final system. Four major steps in developing a computer application are as follows: formal specification or requirements, writing the necessary computer code, testing and installing, and program documentation and user training. It is suggested that prototyping can have its greatest impact when it is used by the analyst as a tool to initially develop system specifications, rather than to test specifications produced by traditional analysis. The availability of a working model allows users to clearly understand how the system works and what information is available. In addition, users have a working system to use while a final production model is being programmed and installed. A case study of the application of prototyping for the personnel system at Canisius College illustrates this approach. (SW)