How do you know what to prototype? What details are important to get right? What level of interactivity is necessary to get valid feedback? Prototypes are very effective tools for playing out ideas, testing concepts and getting feedback. But they are often left out of the design and development cycles due to their disposable nature. It can be tough to justify the effort to make something for the purpose of experiment. Finding the right prototype medium and minimum level of detail required is essential. Without it, how will you get the stakeholder buy-in and funding? Learn how to match your prototype fidelity to the information you need to gather. Understand the range of prototype techniques and match them to your situation. Get maximum value and minimize your project risk.