Many educators and parents would agree that it's important for parents to spend time in their children's classrooms, to closely monitor homework, or to read to children at home. Try telling that, though, to a 13-year-old, argues Nancy E. Hill, an education professor at the Harvard Graduate School of Education and the university's Radcliffe Institute for Advanced Study. In a series of studies and a new book "Families, Schools, and the Adolescent," Hill makes the case that both research and policy initiatives aimed at promoting parent involvement fail to take into account the distinct needs of adolescents, a group of students that seems biologically driven to break free of parental vigilance.