The methodology used in the study from Italy[1] mentioned in the article was quite interesting, because it had actual random assignment of comparable groups of students to different instructors. The students were then followed up over their further study in the same university. That's a good kind of data set to have for examining issues like this.

The alternative means of evaluating teachers mentioned in the article are also quite reasonable. Both peer review and content analysis of instructor-prepared materials can identify better teachers with different sources of bias in the evaluation, allowing a triangulation with student ratings.

Here on Hacker News, from another participant, I learned about a more rigorous method of student ratings of teachers[2] that ought to be applied (with appropriate adaptations) to higher education teaching. It appears to work will in K-12 teaching.

[1] http://www.sciencedirect.com/science/article/pii/S0272775714...

[2] https://news.ycombinator.com/item?id=4559682