Visualizing Practical Performance Measurement

Stephen Few points to an upcoming book: ...  Practical Performance Measurement by Stacey Barr. Plan to read this. I like the idea that he is working with her.  This combines the two key questions due any good data visualization. 1.) Are we visualizing the right things?  and 2.) Are we visualizing them in the best way? Once you have 1 and 2 correct, I further suggest that we should ask 3.) How can we let the user of this visualization interact with it to focus it better on their needs?