Passage Summary: An educator points out that kids whose parents were trained to teach them at home are doing better in school than most other kids. Based on this success, the educator thinks we should roll these programs out to more people.

Conclusion: The educational programs that train parents to teach their children at home are successful and should be expanded.

Reasoning: Children whose parents participate in these 'first teacher' programs demonstrate higher-than-average academic performance in school.

Analysis: The educator sees a correlation—kids in the program do well—and assumes the program is the cause. However, this ignores the 'self-selection' bias: parents who volunteer for a program to learn how to teach their kids are likely already more motivated, involved, or educated than the average parent. If these kids were already destined to succeed because of their parents' high level of engagement, the program itself might not be the reason for their high scores. To weaken this, look for an answer that suggests the children's success is due to the type of parents who join the program rather than the training the program provides.