Since no one else has posted, I will post something here. I collect Conceptis puzzles whenever I can find the books at the store. I also like the free puzzles online. I have taught in an alternative middle school and now in an alternative high school in the Chicago area. "Alternative" in this case means teen parents, gangbangers and other kids who have mainly been placed in these programs in lieu of expulsion. These kids are smart, but no one has ever given them any confidence. When I first worked with these kids, I didn't realize that they had never had the "fun" experiences that I had in school. Since they were mainly "in trouble" or behind in their studies, they never ever got to the enrichment activities. I have found that the picture mazes, dot-to-dots and other Conceptis puzzles really open up their minds. They love to do them and they do not realize that they are improving their math and logic skills in the process. They become so much more confident in themselves and their abilities that they improve in their schoolwork. I don't have any quantitative data to support this, just qualitative.