But a mountain of recent evidence suggests that teacher skill has less influence on a student's performance than a completely different set of factors: namely, how much kids have learned from their parents, how hard they work at home, and whether the parents have instilled an appetite for education. If these home-based inputs are lacking, there is only so much a school can do. Schools have your kid for only seven hours a day, 180 days a year, or about 22 percent of the child's waking hours. Nor is all that time devoted to learning, once you account for socializing and eating and getting to and from class. And for many kids, the first three or four years of life is all parents and no school.