Ongoing Teacher Training Does Not Improve Teaching Performance

From The Wall Street Journal, "Study Questions Value of Teacher Development: Report from nonprofit group suggests rethinking ways to boost skills of teachers" by Leslie Brody:

TNTP, a Brooklyn-based organization that trains educators and promotes stringent evaluations, analyzed several years of data from three school districts. It found the districts spent an average of $18,000 per teacher yearly on professional development, including coaching in the classroom, formal feedback, vendor contracts for training and staff time.

Despite that investment, the report found that only three out of 10 teachers in these districts saw their practice improve substantially over two or three years, and two out of 10 teachers saw their performance decline.***The report found that no particular approach to professional development consistently helped teachers get better. When individual teachers improved, their success didn’t appear to be linked to systemic efforts by the districts. [Emphasis added.]