Conversations about teacher professional development are rarely uplifting: professional development largely does not meet teachers’ needs, few teachers are satisfied with professional development offerings, and principals are concerned about the efficacy of professional development. The list goes on and on. Unfortunately, TNTP’s new report—The Mirage: Confronting the Hard Truth About Our Quest for Teacher Development—does little to bring optimism to the discussion.
The Mirage details an uncomfortable truth: as much as everyone from Capitol Hill policymakers to school instructional coaches wishes they knew how to help teachers improve, they don’t. TNTP’s research squashes the widely-held belief that good professional development practices are known, they just haven’t been put to scale. It’s a shocking point that many will be talking about in the days and weeks to come. If you want to sound smart joining in on conversations about The Mirage, here are some helpful talking points that scratch its surface:
Districts spend a lot on teacher development. The districts in The Mirage spend an average of nearly $18,000 per teacher, per year, or six to nine percent of the districts’ annual operating budget, on development efforts (the charter management organization in the report spends an average of $33,000 per teacher or 15 percent of its annual budget). This figure includes staff time and resources that are intended to improve instruction either directly or indirectly. At this rate, TNTP calculates that the largest 50 school districts in the U.S. devote at least $8 billion to teacher development.
But money isn’t resulting in improvement. As measured by evaluation scores, most teachers do not improve substantially year to year. Only 30 percent of teachers that TNTP studied improved their performance substantially over a two to three year period.  TNTP could not find anything that distinguished teachers who improved from teachers who did not improve. The professional development activities they participated in and the frequency with which they participated in them were virtually identical between teachers who improved and those who didn’t improve. These two groups of teachers also had strikingly similar perceptions and beliefs about development.

Differences in teachers’ growth can’t be explained. TNTP identified professional development as efforts carried out by districts, schools, and teachers themselves. To collect their data, TNTP used multiple measures of performance to identify teachers who improved substantially, then looked for any experiences or attributes these teachers had in common. Turns out, TNTP found no trends. For example, 24 percent of all teachers deemed “improvers” reported the most time spent in extended professional development activities. Meanwhile, 26 percent of improvers also reported the least time spent on the same thing.
Teachers are plateauing before they master essential teaching skills. TNTP confirmed what other research has found: teachers’ growth plateaus after the first few years of teaching. That may not be all that problematic if teachers mastered the skills and knowledge necessary, but according to TNTP, they typically don’t. Of the teachers TNTP studied, as many as half in their tenth year or beyond were rated below “effective” in core instructional practices.
Few people agree on what teacher improvement means and what good teaching looks like. Lots of problems stem from this point. Teachers in TNTP’s survey report feeling like professional development systems are disjointed and impersonal and aren’t customized to fit their needs. It’s no surprise then that the teachers in TNTP’s study seem skeptical about the usefulness of the support they receive.
TNTP’s research is limited in scope: the study included only three large public school districts and one midsize charter school network.  However, whatever conclusions readers walk away with, The Mirage presents empirical data on professional development that has been lacking. The report is bound to start a worthy conversation about what we think we know about teacher professional development.