If pressed to provide a predictor of academic success, most people would choose socioeconomic status (SES). SES is a strong predictor when one looks at averages, but everyone knows that there are individual students of high wealth who are academic disasters and students of low wealth who are academic marvels. Wayne Hoy and colleagues, in numerous studies, have determined that collective efficacy is "more important in explaining school achievement than SES." This is news "of practical significance because it is easier to change the collective efficacy of a school than it is to influence the SES of a school." What is "collective efficacy?" Hoy defines it as "the perceptions of teachers in a specific school that the faculty as a whole can execute courses of actions required to positively affect student achievement." Hoy says that school leaders need to "lead in ways that promote mastery experiences for teachers." And that means, among other things, making sure there are adequate resources and time to develop skills. Professional learning experiences in which teachers practice mastery should be accompanied by opportunities to see it modeled. Which sounds a lot like (because it is) coaching and/or mentoring. Hoy summarizes these findings by writing that "the consequences of high collective efficacy will be the acceptance of challenging goals, strong effort by teachers, and persistence in effort to overcome difficulties and succeed."