I have heard so called “traditional” and “strict” ashtanga instructors say that there is no positive reinforcement given in this tradition. Here is a great blog that shows that indeed people do get positive reinforcement in Mysore. This is an excerpt from Susananda’s Blog that can be found here.
I’d managed a nice vrshchikasana on Tuesday in front of Sharath (this is hanging out in handstand with your feet on your head). He told me ‘very good!’, then stood in front of me for assisted backbends. He stands very close. ‘Legs were shaking’ he said and chuckled… our eyes met and there seemed to be some complicity between us… it’s hard to stay still there without your feet bobbling around… it’s a hard posture! Then he took my hands onto my kneecaps, told me ‘very good’ again, and I trotted off to the changing room for finishing postures feeling rather special.