Debunking the myth of the teacher performance plateau

The disheartening myth that teachers peak as professionals early in their careers and then hit a performance plateau originated from a handful of studies (e.g., Boyd et al., 2008; Kane, Rockoff & Staiger, 2008) and has become a sort of conventional wisdom — one that, if taken at face value, suggests teaching is, at best, a trade that can be grasped quickly. If that were the reality, then the best way to manage such a labor pool would be to hire people with the right background, train them up quickly, and remove those who do not meet a minimum bar of proficiency. Schools and districts would not need to invest much time, money, or attention into teachers’ continual professional development and growth. 

As it turns out, though, newer and more sophisticated studies challenge both the validity and accuracy of this conventional wisdom and reveal a major shortcoming in the earlier studies: They failed to track individual teachers over time and instead assessed the average performance of large cohorts of teachers based on their years of service. As school systems have developed richer data sets that follow the same teachers over time, a clearer and more positive picture of their performance trajectories has emerged. It shows that teacher performance does improve dramatically during their first few years on the job and continues to improve in subsequent years, albeit less dramatically (Harris & Sass, 2011; Papay & Kraft, 2015). Like fine wines, teachers generally appear to keep getting better with time. That’s good news.