In my professional opinion, if your performance work is to have any credibility then you need to agree with and abide by this philosophy. I think it’s really what separates the real experts from the amateurs.
"”Measurement is the first step that leads to control and eventually to improvement. If you can’t measure something, you can’t understand it. If you can’t understand it, you can’t control it. If you can’t control it, you can’t improve it.” - Dr. H. James Harrington