This is about identifying the end users. Identify the people who will be affected by the problem and incorporate them into the discussion of problem articulation. This can mean small group or focus group discussions if they are representative of a larger group of people. Understand how these people will be affected by the project. One approach to think about this is to have a solution trial run. Assuming you can answer the problem, ask yourself if you can use the answer and whose life will change as a result.