What makes a great teacher?

Great article in the Atlantic on how Teach for America has spent the last many years figuring out what makes some teachers able to move their kids ahead while others stagnate and fail. "Those who initially scored high for 'grit'—defined as perseverance and a passion for long-term goals, and measured using a short multiple-choice test—were 31 percent more likely than their less gritty peers to spur academic growth in their students." Having a master's degree is not a determiner of classroom effectiveness they found. The article is linked here.
Ripley, A. (2010). "What makes a great teacher?" The Atlantic , Jan/Feb. Accessed 2/9/2010 at http://www.theatlantic.com/doc/201001/good-teaching