Most people assume that 60 percent to 90 percent of the group given the clue would solve the puzzle easily. What’s more, in statistical terms, this 5 percent improvement over the subjects of Guilford’s original study is insignificant.
In other words, the difference could easily be due to what statisticians call sampling error.
Because they hadn’t, they were obviously not as creative or smart as they had previously thought, and needed to call in creative experts. The nine-dot puzzle and the phrase “thinking outside the box” became metaphors for creativity and spread like wildfire in marketing, management, psychology, the creative arts, engineering, and personal improvement circles.
Even though they weren’t instructed to restrain themselves from considering such a solution, they were unable to “see” the white space beyond the square’s boundaries.
Only 20 percent managed to break out of the illusory confinement and continue their lines in the white space surrounding the dots.
No one, that is, before two different research teams—Clarke Burnham with Kenneth Davis, and Joseph Alba with Robert Weisberg—ran another experiment using the same puzzle but a different research procedure.
Both teams followed the same protocol of dividing participants into two groups.