Often clients will have an idea, some initial designs, or even a developed proof of concept but no real insights about their users and whether their product solves a real problem for them. To prevent failure, we need to validate the concept against user needs. In this workshop, you will learn (and practice) how to guide your client to define target groups and critical use cases and how to combine interviews and usability testing to validate these assumptions. This process proved time and again its value to clients. Interviewing provides the necessary understanding of the users that will guide the decision-making on a high level. Usability testing provides more concrete proof that the concept resonates with intended users. Finally, through this process, clients learn the benefits of the user-centered approach without making a huge upfront research investment.