Observe data collection at the moment of measurement See, observe, learn how data are collected at moment and place of measurement. "You never learn more about a process than when you directly observe how data are actually measured," said Cuthbert Daniel, a superb applied statistician. See with fresh eyes. Walk around what you want to learn about. Talk to those who do measurements. See how numbers came to be. Do those measuring know the desired answer? Are those measuring skilled, alert, honest, biased, incompetent, sloppy, tired and emotional?...Artifacts and errors in measurements measured? How are outliers adjudicated? Edward Tufte, Seeing With Fresh Eyes uxmeasurement
Haven't you noticed? I remember my mother sitting me down at the age of about five with pencil and paper to draw an acacia tree in the yard while she busied herself with her own sketchbook. After a while she came over to see my efforts. “Splendid! But haven’t you noticed how the trunk narrows as it rises? And see how the branches flatten out sideways, not like that oleander over there, where they all go up at a steep angle. Now don’t rub that one out, just do another drawing to compare with the first one.” Jonathan Kingdon, In the Eye of the Beholder Looking Closely is Everything seeing