Luke Chung, president and founder of a software development company in Tysons Corner, volunteered many times to help the Fairfax County school system with computer and business issues. He was a nice guy, so when the county needed to fill two slots reserved for outsiders (what educators often call non-educators) on the Teacher Performance Evaluation Task Force, he was appointed.

He might have seemed to some a genial innocent who would not get in the way of the teachers, principals and administrators who were the majority. But Chung was an experienced manager motivated to nudge the task force in new directions. He revealed in his company blog his astonished reaction to the key issue:

“As an outsider who has never been evaluated as a teacher, you can imagine my surprise to discover that although principals were judged by their school’s student performance, student performance is not part of a teacher’s performance evaluation in our county,” he wrote. “Are you kidding me?” Chung’s italics, not mine.

He got the basics. “Not all students are equal, and we don’t want to have a system where teachers are evaluated solely on student performance because the incentive would be to only want to teach good students,” he wrote. He saw some sense in value-added measurements, rating teachers on how much their students improved. But there were practical problems, he said, “such as kids moving in and out of classes within the year, impacts on kids outside teacher control, whether the test is a good measurement, multiple teacher collaborative environments, etc.”

As an entrepreneur, he isn’t afraid of ideas. After much thought, he has come up with an approach to teacher evaluation that is rare if not altogether new in the national evaluation debate.

He thinks teachers should evaluate other teachers, but in a specific way. Downstream teachers should assess upstream teachers, as Chung puts it. That means a teacher should evaluate the teachers who had her students in their classes the year before by judging what those students brought with them to her class, including behavior, curiosity and other non-tested traits.

He asked himself: Who benefits and pays the most for good or bad teaching? He said he concluded that students do, but they must not evaluate teachers because of the conflict of interest. Parents have a stake, but being a parent himself, he says, “I would hardly consider parents qualified to really know what’s going on with individual classes.” Bureaucrats produce broad requirements, he says, but “they’re hard-pressed to come up with specifics for evaluating a particular teacher.”

He was left with certain teachers as key evaluators. “Essentially, a teacher receives kids from upstream, trains them and then passes them off to their next downstream teacher,” he said. “Looking at it more like a production line, the teacher is a huge beneficiary and victim of good and bad teaching, more than anyone else in the system other than the student. Teachers should be empowered to define expectations and evaluate their upstream teachers for their performance.”

Chung says teachers told him they knew which teachers were good or bad overall, and who had skills appropriate for different types of student personalities.

School districts have tried teachers evaluating other teachers, but in a more general way. Systems such as D.C. public schools rate teachers in part by how much each of their students improves on standardized tests, but a downstream teacher would probably see improvements the tests missed.

The Fairfax County task force gave Chung’s idea a polite, but not particularly warm, reception. “The concept that more junior downstream teachers would evaluate more senior upstream teachers may be too foreign and frightening for some to accept,” he said.

The idea does offend some sensibilities. But if teacher evaluations are going to include multiple measures, as all the experts say they should, shouldn’t what teachers think of other teachers have some weight?