The first step in prototyping is to identify the biggest questions or most important assumptions that you have about how users will interact with your solution and whether it addresses a real need and has recognised value. These might be questions that arose during Ideation activities, or from assumptions captured during the Recognition stage. Give that your aim is to expend the least amount of time, effort and cost necessary to test the most critical elements of your concept, you will want to prioritise your research questions according to those that are most important and easiest to test. Use our 2×2 Priority Matrix to carry out this task.