Jo Boaler:

When New York City’s mayor began a move to revamp the program of selective schools last year, a public outcry ensued, and the issue has yet to be resolved.

Objections echoed those in the San Francisco Unified School District, which six years ago began in earnest the elimination of advanced mathematics classes until after 10th grade. Parents created Facebook groups to oppose the changes.

Many believe that children learn more effectively in schools or classes with similar learners, but are they right? It is a question that has long intrigued and divided people. When learners show different achievement levels, should we teach them separately or together? I have spent my career studying this question and, although the logic of separate classes seems strong, evidence leads us in a different direction.

For instance, after San Francisco Unified de-tracked math, the proportion of students failing algebra fell from 40 percent to 8 percent and the proportion of students taking advanced classes rose to a third, the highest percentage in district history. Until 10th grade, students take the same mathematics classes. From 11th grade on, students can choose different pathways.

Related: 2006: “They’re all Rich White Kids, and they’ll do just fine, NOT!”.