Effective prototyping for usability

People designing software with a usability perspective use a variety of techniques to engage prospective users in a dialog about the target application´s functionality and interaction model. The authors discuss how and when they have been able to use prototyping techniques to maximize the value of this dialog. They review several widely used approaches to prototyping and evaluate them along the dimensions of fidelity and interactivity. Subsequently, they posit a number of objectives that they have established for a usability oriented prototyping system, and consider the pros and cons of adapting an existing tool or building a new one. Finally, they close with some thoughts that contrast prototyping with simulation modeling