Yolande Beckles takes a traditional approach to discipline and in Don’t Mess With Miss Beckles (BBC2, March 28, 9pm) directs her motivational skills at under-achieving GCSE students Luke and Josh. We learn salutary lessons here, one being that such documentaries don’t always work out as planned. “I wish it was the perfect ending,” says Luke’s mum, sadly, as the film ends. She and Yolande, like Luke’s teachers, will just have to be content with small improvements.