Tom Ultican, retired teacher of physics and advanced mathematics in California, wrote a devastating critique of the latest CREDO charter school study, based on the analysis by the Network for Public Education.
He wrote:
The Center for Research on Education Outcomes (CREDO) just released another pro-charter school study, “CREDO also acknowledges the Walton Family Foundation and The City Fund for supporting this research.” It is not a study submitted for peer review and is so opaque that real scholars find the methodology and data sets difficult to understand. Carol Burris and her public school defenders at the Network for Public Education (NPE) have provided an in-depth critical review.
With the new CREDO study, Education Week’s Libby Stanford said that “charters have drastically improved, producing better reading and math scores than traditional public schools.’’ Rupert Murdoch’s Wall Street Journal declared charter schools are now “blowing away their traditional school competition.” Burris retorted with “despite the headlines, the only thing ‘blown away’ is the truth.”
Putting a CREDO Thumb on the Scale
CREDO uses massive data sets, unavailable to other researchers, getting minuscule differences which are statistically significant. No one can check their work. They employ a unique and highly discredited statistical approach called “virtual twins” to compare public school with charter school testing outcomes. Instead of reporting the statistical results in standard deviations, CREDO uses their “crazy pants” days of learning scheme.
NPE discovered that the “blowing away” public school results amounted to 0.011 standard deviations in math and 0.028 standard deviations in reading. The minuscule difference is “significant statistically but is meaningless from a practical standpoint” according to CREDO. In a 2009 report showing public schools with a small advantage, CREDO declared, “Differences of the magnitude described here could arise simply from the measurement error in the state achievement tests that make up the growth score, so considerable caution is needed in the use of these results.”To give these almost non-existent differences more relevance, CREDO reports them as “days of learning”instead of standard deviation. “Days of learning” is a method unique to CREDO and generally not accepted by scholars. They claim charter school math students get 6 more “days of learning” and English students, 16 days.
Please open Tom Ultican’s post to see why he considers the CREDO report to be “sloppy science” and “unfounded propaganda.”
Diane Ravitch's blog 
Analyses remain, only as
good, as the assumptions
they are built on.
Do “Real Scholars”
assume scores are
more than concocted
metrics?
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Also, not discussed in the so-called virtual twins, that is disclosed in numerous reports, is the fact that public school and charter school enrollment patterns are not the same by virtue of the fact that public schools take ALL students while charter schools have the right of refusal and rely of a variety of ways to sort out those they deem “less capable.” Charter schools have ways to exclude students, and they generally enroll fewer classified students and ELLs. Burris points out that the classified and ELLs are not a monolith. If charter schools accept any of these students, they are generally the highest functioning in these subgroups.
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credo.stanford.edu
Stanford, the think (spin) tank with students and a reputation for truthyness (or, falsification).
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I’m very thankful that educators like Tom and orgs like the NPE are there to debunk CREDO’s corporate propganda.
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Thanks ArtsSmart. We can always use more people writing and supporting NPE. Come to the NPE conference the last weekend of October in Washington DC.
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6 days. Plenty of time for God, but hardly enough to make any difference in the life of a student. Probably not enough time for a mere mortal to read Les Miserables or derive a new proof of the Pythagorean Theorem.
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👍 ❤️
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Reblogged this on Crazy Normal – the Classroom Exposé and commented:
Outside of court, thanks to the 1st Amendment, everyone is free to lie all they want, and the extreme right and the billionaires that fund that fascist movement take advantage of that all the time. This is another example.
What you read in the pull quote below is ALL LIES, with the facts used to support those lies manipulated, cherry-picked and the source material hidden.
“With the new CREDO study, Education Week’s Libby Stanford said that “charters have drastically improved, producing better reading and math scores than traditional public schools.’’ Rupert Murdoch’s Wall Street Journal declared charter schools are now “blowing away their traditional school competition.” Burris retorted with “despite the headlines, the only thing ‘blown away’ is the truth.”
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DOH! EdWeek & WSJ buy-in to CREDO study is as doggy-panting as the sky-is-falling MSM reaction to post-pandemic NAEP scores. Just as uninformed & statistically unsupportable. So far at least, I haven’t seen the same degree of MSM buy-in. Perhaps their reporters have learned, at minimum, to google “criticism of credo study methodology.”
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