Good teachers need prep....Are you listening Arne? Barack?

From the New York Times blog, "Room for Debate".
Good teachers must also be connoisseurs of error. Over time, good teachers can anticipate predictable errors and misconceptions, understand the logic behind the error, and help move students toward a deeper understanding. . . . So those who are thinking of teaching should be prepared for a steep learning curve in the first few years on the job. .....