“What should we think of someone who never admits error, never entertains doubt but adheres unflinchingly to the same ideas all his life, regardless of new evidence? Doubt and skepticism are signs of rationality. When we are too certain of our opinions, we run the risk of ignoring any evidence that conflicts with our views. It is doubt that shows we are still thinking, still willing to reexamine hardened beliefs when confronted with new facts and new evidence.”

"When a school is successful, it is hard to know which factor was most important or if it was a combination of factors.Even the principal and teachers may not know for sure. A reporter from the local newspaper will arrive and decide that it must be the principal or a particular program but the reporter will very likely be wrong. Success, whether defined as high test scores or graduation rates or student satisfaction, cannot be bottled and dispensed at will. This may explain why there are so few examples of low-performing schools that have been "turned around" into high -performing schools. And it may explain why schools are not very good at replicating the success of model schools, whether the models are charters or regular public schools."