Perhaps the dominant theme in this book has been improvement. For improvement to occur, we must be willing and able to learn, accept valuable feedback, and use feedback to adapt as required for the performer and performance system to thrive. Much research has highlighted the power of feedback in improving performance. Evaluation is a central mechanism by which we can obtain purposeful feedback. It is in this context that I hope readers will see the value of evaluation and that all will see evaluation as an integral and required part of everything we do rather than as an isolated and unnecessary use of resources.