There are many ways to improve knowledge about teaching. Many teachers practice personal reflection on teaching; that is, they look back at what has worked and has not worked in the classroom and think about how they can change their teaching strategies to enhance learning.
(Hole and McEntee (1999) provide useful steps for enhancing such reflection.
A few teachers (most notably Education professors) conduct formal empirical studies on teaching and learning, adding to our knowledge base.
(CAR) fits in the center of a continuum ranging from personal reflection at one end to formal educational research at the other.
(CAR) is more systematic and data-based than personal reflection, but it is more informal and personal than formal educational research.