Imagine the worst possible reports from a system. What is wrong with them? List as many problems as you can. What are the consequences of such reports? What could go wrong as a result? How does the prototyping process help guard against each problem?
Describe the characteristics of the worst reports. Consider different aspects of the report that could go wrong such as format, layout and content, and describe what could go wrong with them under different categories. E.g. the content could be wrong if it has late info, irrelevant info, wrong info etc.
Describe the consequences.
Discuss the benefits of prototyping. Users are involved early and have immediate feedback so above issues are generally identified early and fixed in time.