The key words are: my bias. What the students went on to teach me is that the problem is that the "smart" kid dominates the group. Other students want to help, want to participate, want to learn, but the smart kid won't let them get an idea in edge-wise. I had never thought of it from that angle before. I was an A student in school, at least academically. After the focus group, I think I may need to apologize to some old classmates for getting a D in "works well with others."
6 years ago