I've collected data on green speed and on dispersion of golf balls as they roll across a putting green. The analyses I've made of these data are not so much about the exact measurements, or the average of the measurements, but more about the variation in the measurements. That is, what is normal variation if I measure green speed at location X on green 1 and then move to location Y on green 1. Is the speed identical? What if it varies by 7 inches, is that normal, or is that unusual? What is the normal variation in green speed from all 19 or 20 greens at an 18 hole facility? What is abnormal variation? And what is normal dispersion of ball roll across a green? What is abnormal dispersion?