Help wanted – any statisticians out there?

We know that a great teacher can make a huge difference to a class, and the whole debate today focuses on the way to get more great teachers, and allowing them to make even more impact.

The thing is, data I’ve been looking at seems to suggest to me that the variation in any teacher’s quality is pretty huge compared to the variations between teachers. This would suggest that many teachers are capable of delivering some great lessons, but that most of them are inconsistent. If this is true, the focus could be much more about collaboration, about getting teachers to have more great lessons, and less on the blunt “good teacher/bad teacher” labels.

Trouble is, despite being an A-level maths teacher, I wouldn’t say my statistics is top-research-quality, and I wondered if there was someone out there who might help me?