Me too. At least they show how entries are being selected for comparison. One thing that always frustrates me when watching videos like the one linked in the main post is when teachers try to use a real world example where agency is involved (like students ordering themselves by height). In the video he says "The shortest person in the class, he _knows_ his place. He will quietly come and stand in the beginning of the list." Data _doesn't_ know. It needs some external process to determine its place.