TULSA, Oklahoma - Friday is the first of the new "early release" days for Tulsa Public Schools, when the district will turn out classes so teachers can use the time for training.

The district has started "Professional Learning Communities," where small groups of teachers, for example the 4th grade team from a school, can spend time together focused on changes in strategy for better teaching.

TPS Superintendent Keith Ballard said the PLC's are important, because generally teachers work in isolated classrooms and don't have a chance to work together on improvement.

"There's research that shows when teachers look specifically at data and trends in the data and make adjustments, that student achievement does improve. The research shows it's a very powerful learning tool and that's why we're doing it" said Ballard.

The release time will vary by school.