Linda Darling-Hammond of Stanford University offers common-sense ideas about closing the achievement gap. She says that testing is less important than teaching. No surprise there.

She reviews an OECD study about teachers. What it shows is that teachers in the U.S. work longer hours under more difficult conditions than teachers in many other nations.

“Now we have international evidence about something that has a greater effect on learning than testing: Teaching. The results of the Teaching and Learning International Survey (TALIS), released last week by the Organization for Economic Cooperation and Development (OECD), offer a stunning picture of the challenges experienced by American teachers, while providing provocative insights into what we might do to foster better teaching — and learning — in the United States.

“In short, the survey shows that American teachers today work harder under much more challenging conditions than teachers elsewhere in the industrialized world. They also…