Spinning Experiment Analysis, continued...

I am fully occupied with sorting through some stuff here, trying to stow tools and materials in a better way than before, getting my textile technique demonstration projects maintenanced and ready to show things again, plus planning for and working on some stealth projects.

And I have one non-stealth project to blog about, too: My "Fehlerschautafeln" have arrived! These are rectangular black cardstock boards with slits punched into each of the long sides. Using these slits, thread can be wound onto the card and then sits in exactly parallel lines. And then it's very easy to get an impression of how evenly spun the thread is, if it is smooth or rather fluffy on its surface, if there are any thick blobs of fibre or badly twisted bits, and so on. Now I just have to decide how to handle all the thread samples with their vastly different lengths - should I start winding about five metres in, where possible? And if yes, from the beginning or from the end? Or should I try to get the middle section of each thread? Going "x metres in" would be much easier to accomplish, but I am willing to do the "more work" approach if there is a good reason for it; however, the method has to be the same for all the samples (except the utterly short ones where I'll use an alternative method of determining where to start).
I can wind about 3,5 metres on each of the boards; most of the spinners made between 30 and 40 metres of thread during the one hour spinnng time. 3,5 metres would thus correspond to about 6 minutes of spinning time.

Now, if you spin for two hours, and there's a sample from hour one and from hour two - when in each hour would you suspect are the most representative six minutes to pick?