The implications of New York's Common Core-aligned test results are still reverberating, particularly for the state's English Language Learners (ELLs). While the recent, more rigorous tests deemed 31 percent of students proficient at math statewide, that figure is only 9.8 percent for ELLs.

These developments make research from Benjamin Masters and his colleagues at Stanford particularly timely. Last year, they delved into the characteristics and training of teachers who were differentially effective in improving the math achievement of ELLs. Why only math? The city changed its English Language Arts testing schedule partway through the study's timeline, creating limitations in data interpretation. Still, math proficiency depends on understanding the language, and these findings provide some guidance for how teachers boost learning for ELLs.

They found that learning instructional strategies specific to ELLs during teachers' preparation programs was highly predictive in boosting ELLs' math achievement. Teachers participating in PD focused on teaching ELLs in the first semester of their first year were a lot more effective (30 percent of a standard deviation within the same year) than those who did not. Earning an ELL endorsement before entering the classroom was also associated with greater teacher effectiveness with ELL students (11 percent of a standard deviation).  These are large effect sizes for education, and focusing on these areas could have a real impact on the ELL achievement gap.

The authors conclude "the improvement in ELL effectiveness among teachers who gain experience teaching ELL students provides credible evidence that a distinct skill-set is valuable for teaching math to ELLs and that these skills can be learned through practice." Unfortunately, researchers did not investigate the specific instructional strategies that these forms of training provided, but it seems that a common denominator is giving novice teachers more opportunities to practice their craft.

These findings confirm a central point of the Teacher Prep Review: focused, practical training does have an impact on new teacher effectiveness. Now the challenge is to identify the particular strategies that seem to have had the greatest impact and make sure that all new teachers get them.

Master, B., Loeb, S., Whitney, C., & Wyckoff, J. (2012). Different skills? Identifying differentially effective teachers of English language learners.