How to get the balance between "Trust " and "Control"?

What happened to the Genesys was the students were likely to concentrate on products which would be inspected by tutors or clients. For instance, most of the project teams spend much time on writing Requirement Specification (which would be inspected by tutors and clients) and coding, but unit testing and refactoring were often neglected by them. When the tutors decided to check their testing results, 6 of 8 project groups were found not to have written the unit test , though they had been asked to write test before coding. But the situation was changed rapidly after they knew the test case would be inspected.

How many trusts should be given to the developers?

In some companies, one of the Senior Developers is chosen to take the responsibility for technical problems, as well as evaluation the performance of the group members. This is one of ad hoc solutions. The better solution should be allocate a full time or part time QA to take full responsibility for process tracking and control including code and test inspection; tracking , recording and evaluation the process and performance with the help of management tools . The aim is to give enough feedback for adjust the XP process and planning for the coming iterations.

Does the XP need the process control? Does it need Configuration Management, Code Inspection, and Test Case Inspection? How to keep the balance between TRUST and CONTROL ? How to evaluate the performance of each members while they have Collective Ownership of the code ?