An effective instructional coach needs to be both a demanding drill sergeant and an indomitably chipper cheerleader. After all, two of the key ingredients to helping teachers improve are accountability and positive feedback. Accountability will help teachers stay focused on making changes that stick; and targeted positivity has even bigger implications. After all, seeing evidence of their own improvement will subtly shift a teacher's mindset about the daunting task of growing as an instructor. It's at this point--when a coach is affecting both a teacher's moves and her attitudes--that real growth can occur.