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Excellent Pie Chart On What Influences Student Test Scores


The finding that at least two-thirds of the factors influencing student test scores are outside of a teacher’s control is well-researched and pretty commonly accepted. You can find all that research at The Best Places To Learn What Impact A Teacher & Outside Factors Have On Student Achievement.

Today, I saw this tweet that provides an excellent visual of those findings:

As the tweet says, it comes from a report by Edward H. Haertel, emeritus professor of education at Stanford. The report was published by Educational Testing Service.

I previously posted
about a talk Professor Haertel gave on his report, which included a video, but didn’t highlight this particular pie chart.

In case you missed it, here’s a quote from his talk that I highlighted in that post:


Author: Larry Ferlazzo

I'm a high school teacher in Sacramento, CA.


  1. Thanks for sharing this pie chart… I find it useful as we explain to non-educators about WHY VAM is a SCAM. I think my favorite quote from his lecture text is “Teacher VAM scores should emphatically not be included as a substantial factor with a fixed weight in consequential teacher personnel decisions.”

    Thanks again.

  2. The chart is very useful. Thank you.

    But the major point we are not making is that the “out of school factor” is the racial wealth gap – now 20 to 1 between the median white family and the median black family; 18 to 1 between the median white family and the median Latino family. (Pew Trust; Insight Center) Those wanting to make profit out of education are blasting educators; we need to be blasting back. Societies with more equal distribution of wealth and social services have more equitable school outcomes. Defending teachers is fine, but the bigger point is making clear where the real problem lies.

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