The quality of the teacher doesn't affect how much students learn (that doesn't mean it doesn't affect other factors - e.g., interest and motivation).
Low ability students learn just as much as high ability students when exposed to the same experiences.
More able students learn more because they seek out other learning opportunities.
Tests, more than measuring a student's learning, reflect the student's motivation.
In the discussion over learning styles and measuring achievements, it's important to take into account what educators see first-hand in class. To get a sense of their perspective on the subjects, I asked educators who are part of the Powerful Learning Practice to weigh in on what they've observed in their classrooms. Here's what they say.
Krechevsky and Stork (2000) stress the importance of learning from other people, as opposed to individual learning, but lament that 'many of our cultural images of teachers, parents, children and schools themselves stand in the way of realising such communities of democratic participation'
Our school (NBCS) is going through a major reform of not only teaching styles and pedagogy but learning space, both physical and virtual. If you would like to see some of the blog posts by my principal about this visit http://imaginelearning.tumblr.com/.