3. Explain why software testing should always be an incremental, stage activity. Are programmers the best people to test the programs that they have developed?

4. Explain what the rapid delivery and deployment of new systems, used in agile practices, is often more important to businesses than the detailed functionality, presented in a document, of these systems.

5. Explain why test-first development helps the programmer to develop a better understanding of the system requirements. What are some potential difficulties with test-first development?