I get really annoyed when I hear of students receiving such bad instruction they do not at least understand how to carry out simple turns. I used to be an ATC gliding instructor and you have to be able to teach everything in 3 minute chunks using very efficient patter. Now I always offer my passengers in an SEP a go on the controls and I cannot remember one who couldn't do simple turns after one short demonstration of primary effects of controls along with a little patter to draw their attention to small changes in pitch. Some were obviously better than others and some would lose there coordination after about 10 minutes but everyone could understand what they were doing and why.