Runout is the measurement of the eccentric motion in a rotating body. What I have been talking about in terms of a record is that the center axis of the record grooves are not matched precisely to the center axis of the platter. (Shaft runout would normally be measured in V-blocks in a lab and would consist of a combination of roundness as well as straightness of the shaft.) Additionally, the platter can have some runout- hopefully that is nearly unmeasurable considering the cost of some of these platters. The best way to measure the runout of a record would be to measure the swinging motion of the tonearm when it is playing a round groove at the inner diameter of the record. It would be difficult to measure while playing in the music groove since the tone arm is continuously moving inward towards the center of the record. The OD of the record is likely not that round and not necessarily tied dimensionally back to the music groove. I would say that if you can discern a swaying motion in the tonearm with your eyes as it is running in the music groove, then the runout is probably high. This was the case with my test record. But even then, I could hear the Wow only when playing pure test tones.