Jay Mathews on Class Size

The Washington Post's Jay Mathews, one of the nation's premier education journalists, has an important column today summarizing the research on class-size reduction:

...[W]hen the Center for Public Education examined 19 studies of class-size effects that met its research standards, it reached two interesting conclusions. First, most of the studies focused on kindergarten through third grade, and most of the beneficial effects of smaller classes seem to occur in those years, when students are learning to read....Second, the studies showed little effect from class-size reduction unless the number of students was 20 or fewer, and little effect in middle or high schools.

The whole article is definitely worth reading -- particularly for its "thought experiments" for parents and for administrators.