Historically, professional development for teachers has been dominated by daylong seminars that took teachers out of the classroom and delivered the same tips and tricks to an entire department, grade level, or school. But as research has found, these programs to have little or no effect on teacher quality. Some training has shifted to a customized, smaller-scale approach: instructional coaching, whereby an expert mentor works one-to-one with teachers to provide a steady stream of feedback and suggest new techniques based on frequent classroom observations. By the 2015‒16 school year, 24 percent of public K-12 schools had a general instructional coach, according to the National Teacher and Principal Survey. To learn more, read “Taking Teacher Coaching to Scale” on EdNext.org or in our Fall 2018 issue.