HOW EXPERTS MOTIVATE

Mark Lepper, a social and developmental psychologist at Stanford University, has studied the paradoxical effect of external motivations: how, when people feel they are being pressured, they often react badly -- and lose their inner drive.

But that does not mean external motivation never works. In an analysis of expert teachers, Lepper found that they regularly came up with ways to boost their students' internal drive.

Where inferior teachers might praise students indiscriminately, Lepper found that when it came to encouraging students to solve a puzzle, the best ones used praise sparingly and carefully. Instead of speaking in general terms -- "Boy, you were quick at that" -- these teachers praised students for specifics and focused on the process of learning as much as on the result.

Rather than saying, " 'You are such a smart kid -- you must be a whiz at math,' expert teachers said, 'I can see you are really concentrating. The strategy you had to lay out the puzzle in a systematic way seems like a good idea,' " Lepper said.

The best teachers, he added, also kept finding new ways to encourage curiosity -- keeping tasks challenging, but never so challenging that students wanted to give up.