I am reposting this because the original omitted the link to the article. I went to the car repair shop and the computer repair shop today, and wrote this post while paising in a coffee shop between repairs. Carol Burris’s article links to the original study, which has the ironic title “In Pursuit of the Common Good: The Spillover Effects of Charter Schools on Public School Studenys of New York City.” Ironic, since charter schools have nothing to do with the common good.

Recently, a study was released that made the absurd claim that public schools make academic gains when a charter opens close to them or is co-located in their building. To those of us who have seen co-located charters take away rooms previously used for the arts, dance, science, or resource rooms for students with disabilities, the finding seemed bizarre, as did the contention that draining away the best students from neighborhood public schools was a good thing for the losing school.

The rightwing DeVos-funded media eagerly reported this “finding,” without digging deeper. Why should they? It propagated a myth they wanted to believe.

The author of this highly politicized study is Sarah Cordes of Temple University.

Carol Burris, executive director of the Network for Public Education and a former principal, is a highly skilled researcher. She reviewed Cordes’ findings and determined they were vastly overstated. Her review of Cordes’ study was peer-reviewed by some of the nation’s most distinguished researchers.

Burris writes:

“Cordes attempted to measure the effects of competition from a charter school on the achievement, attendance and grade retention of students in nearby New York City public schools. In addition, she sought to identify the cause of any effects she might find.”

She did not take into account the high levels of mobility among New York City public school students, especially the most disadvantaged.

But worse, her findings are statistically small as compared to other interventions:

“Upon completing her analysis, Cordes concludes that “the introduction of charter schools within one mile of a TPS increases the performance of TPS students on the order of 0.02 standard deviations (sds) in both math and English Language Arts (ELA).”

“To put that effect size in perspective, if you lower class size, you find the effect on achievement to be ten times greater (.20) than being enrolled in a school within one mile of charter school. Reading programs that focus on processing strategies have an effect size of nearly .60. And direct math instruction (effect size .61) with strong teacher feedback (effect size .75) has strong benefits for math achievement[2]. With a .02 effect size, the effect of being enrolled in a school located near a charter school is akin to increasing your height by standing on a few sheets of paper.”

Burris noted that what really mattered was money:

“Although it appears that Cordes found very small achievement gains in a public school if a charter is located within a half mile, that correlation does not tell us why those gains occurred. To answer that question, Cordes looked at an array of factors — demographics, school spending, and parent and teacher survey data about school culture and climate.

There was only ONE standout out factor that rose to the commonly accepted level of statistical significance — money.”

Burris concludes that journalists need to check other sources before believing “studies” and “reports” that make counter-intuitive claims:

“The bottom line is that Sarah Cordes found what every researcher before her found — “competition” from charters has little to no effect on student achievement in traditional public schools. It also found that when it comes to learning, money matters as evidenced by increased spending, especially in co-located schools.

“Most reporters generally lack advanced skills in research methods and statistics. They depend on abstracts and press releases, not having the expertise to look with a critical eye themselves. But it does not take a lot of expertise to see the problems with this particular study.”

Sarah Cordes’ “study” will serve the purposes of Trump and DeVos and others who are trying to destroy the common good. Surely, that was not her intention. Perhaps her dissertation advisors st New York University could have helped her develop a sounder statistical analysis. It seems obvious that the public schools that have been closed to make way for charters received no benefit at all–and they are not included in the study.