Since the beginning of the year I have read several books on psychology and behavioral economics. Books like Brain Rules, Predictably Irrational and Stumbling on Happiness. Latest book is Thinking, Fast and Slow. All these books come to one conclusion, we are not as smart and rational as we think. Our minds literally lie to us, making up past memories to ensure the story we want is plausible. Our minds are extremely susceptible to to biases and anchors, even when we know the bias or anchor is present. Our minds cannot think statistically.
One example from Thinking, Fast and Slow that really caught my attention is the "Law of Small Numbers". In particular, how it relates to the debate on classroom size, a pet-peeve subject for me. I have never been a believer that smaller class size resulted in better education. As someone who did extremely well in school, as measured by grades, standardized tests and acceptance into the the best universities, I knew that class size did not matter. I would have excelled in a class of 5 or 50. What really mattered? My parents stressing the importance of learning. Also that I didn't discover girls and beer until I joined a fraternity in college.
In Thinking, the author cites studies that smaller schools perform better than average and smaller schools perform worse than average. A little surpsiing at first but statistically sound. When dealing with small numbers, randomness doesn't appear so random. Small schools cluster into over-performing and under-performing but overall, smaller schools are no better or worse than larger schools.
This phenomenon also applies to smaller classroom size. Studies at Stanford University showed smaller classroom size having both a positive and negative effect. You are just as likely to find an under-achieving small classroom as a high-achieving small classroom. In the bigger picture, things average out and smaller classrooms are no better off than larger classrooms. There is no causality, just randonmess in small numbers messing with our heads.
So teachers and parents, please stop believing smaller classroom size is the key to a better education system. Just keep your kids away from girls/boys and beer.