It appears that American teachers — well, middle school teachers, anyway — work longer hours than their counterparts in other countries.

And yet our students still don’t perform all that well in comparison to those other countries.

What’s going on?

That is one of the questions raised by a new, intriguing survey of teachers and their principals across 30 education systems done by the Organization of Economic Cooperation and Development as part of the international assessment of 15-year-olds, the PISA exam.

Read the full article on The Huffington Post Education.