NYC releases teachers’ value-added rankings

After a long legal battle, the New York City Education Department released individual performance rankings of 18,000 public school teachers on Friday, “while admonishing the news media not to use the scores to label or pillory teachers,” reports the New York Times.

The reports, which name teachers as well as their schools, rank teachers based on their students’ gains on the state’s math and English exams over five years and up until the 2009-10 school year.

Over the five years, 521 teachers were rated in the bottom 5 percent for two or more years, and 696 were repeatedly in the top 5 percent.

But citing both the wide margin of error — on average, a teacher’s math score could be 35 percentage points off, or 53 points on the English exam — as well as the limited sample size — some teachers are being judged on as few as 10 students — city education officials said their confidence in the data varied widely from case to case.

A teacher’s score can’t be considered in isolation, said the Education Department’s chief academic officer, Shael Polakow-Suransky. “No principal would ever make a decision on this score alone.”

If the margin of error really is that wide, I don’t see any value in the value-added scores.

While Bill Gates editorialized against publishing teachers’ names and scores as “shaming,” Eric Hanushek calls it “prodding”.

 

About Joanne

Comments

  1. Over the five years, 521 teachers were rated in the bottom 5 percent for two or more years, and 696 were repeatedly in the top 5 percent.

    Hahahaha. Out of 18,000 teachers? Wow, that’s meaningful data.

    • Um, Cal, you do understand percentages don’t you? If the data were perfect, the top 5% of 18,000 teachers would be 900. 696 is actually pretty good for data that is collected in the real world over time.

  2. I used to create a score in my classes – attendance compared to grade – there was almost a perfect correlation between the two. The more they showed up, the better they did. If attendance isn’t included, that value-added score would be meaningless.

  3. Now for the Prologue:

    Right-wingers and “reformers” wet themselves in glee

    • Ah yes, the “If you don’t have anything intelligent to bring to the discussion, inject bodily functions” gambit. Well played!

  4. http://www.ny1.com/content/news_beats/education/156599/now-available–nyc-teacher-performance-data-released-friday

    That’s the link to the raw data. I wonder what the reaction will be among parents who find out their child’s teacher is the worst teacher in the school? Well, who really cares, right?

    It only matters if you can do something about it and most parents can’t.