Summary

• An iterative approach to acceptance-test definition is essential to keeping up on XP iterations.

• After iteration planning is the time to work on details visible to the customer, but leave those that aren't (how-to items) to test design and execution.

• Defining details of the acceptance tests is really defining the quality the customer expects of the system.

• The customer does not always want the highest-quality system.

• Producing the customer's desired level of quality when the team has a "higher" standard requires the distinction between internal and external quality.

• External quality is quality as measured by the customer. Internal quality is quality as measured by the programmers.

Try these ideas out yourself in the following exercise.