This morning Sir Ken Robinson tweeted this excellent video clip that is basically a creative thinking exercise done with third graders. The lesson that the video highlights is the importance of how teachers word their questions. Students creativity, as is shown from this experiment, is tightly linked to the way the teacher put his\her question.
For instance, when students were told to complete the painting the "right way", they assumed there is a right answer and this preconceived assumption negatively impacted their creativity in that 80% of their paintings were simple drawings of houses and the average number of colours used were two. Whereas, when they were told to just complete the painting, they used their imagination freely and therefore ended up painting different houses and using a wide range of colours.