In this step of evaluation practice, one must clarify what is needed to resolve the problem, or part of the problem, that has been identified. Before exploring need in detail, let us revisit the distinction between problem and need. As we discussed in Chapter 4, a problem is a value statement about what is undesirable or in need of change. For a problem to be relevant to a professional group it must be within the boundaries and theoretical domains of each profession. For example, even though we would need to be conversant and knowledgeable about the recently posited genetic causes of substance abuse, diagnosing a medical condition would not fit within the professional knowledge base of public health, business, educational, and policy professionals. Thus, if presented with a medical “problem,” these professionals would refer that “problem” to a biogenetic professional.