We once believed that teacher effectiveness dramatically increased for the first three to five years on the job and then plateaued. But recent research suggests that substantial growth in effectiveness can be seen for the first 12 years on the job, and likely longer. This suggests that teacher quality develops over time and that experience can influence effectiveness.
We also know that students who have highly effective teachers for three years in a row can score 50 percentile points higher on achievement tests than students who have less effective teachers three years in a row.
But academic gains are just one of the outcomes of high teacher effectiveness. Research showed that as teachers gained experience, their students’ absenteeism rates declined. Experienced teachers tend to be better at classroom management and motivating students, resulting in fewer conduct issues and higher attendance.
And then there are soft skills, such as the ability to collaborate and problem solve, think creatively, and be empathetic. These skills—which have been linked to higher employment, greater job satisfaction, and lower crime rates—are developed, not taught, and teachers are a huge part of that development.
A costly reality
In the last 20 years, teacher attrition has nearly doubled, and districts are finding it harder than ever to place a highly-qualified and effective teacher in every classroom. And when 16 to 30 percent of teachers leave the profession every year, districts have the very difficult challenge of finding an effective teacher for every classroom.
With a shrinking pool of teachers to choose from, districts are forced to hire less experienced or underqualified teachers to fill vacant spots. This means that at any given time, hundreds of thousands, if not millions, of students in the United States are being taught by subpar teachers; a scary reality since one year of suboptimal teaching can lead to as much as nine months of lost learning, and learning gaps for years to come, according to Scott Reeder’s The Hidden Costs of Tenure.