Evidence and Policy: If You Want to Make a Silk Purse, Why Not Start With…Silk?

Everyone knows that you can’t make a silk purse out of a sow’s ear. This proverb goes back to the 1500s. Yet in education policy, we are constantly trying to achieve stellar results using school and classroom programs of unknown effectiveness, or even those known to be ineffective, even though proven effective programs are readily available.

Note that I am not criticizing teachers. They do the best they can with the tools they have. What I am concerned about is the quality of those tools, the programs, and professional development teachers receive to help them succeed with their children.

An excellent case in point was School Improvement Grants (SIG), a major provision of No Child Left Behind (NCLB). SIG provided major grants to schools scoring in the lowest 5% of their states. For most of its existence, SIG required schools seeking funding to choose among four models. Two of these, school closure and charterization, were rarely selected. Instead, most SIG schools selected either “turnaround” (replacing the principal and at least 50% of the staff), or the most popular, “transformation” (replacing the principal, using data to inform instruction, lengthening the school day or year, and evaluating teachers based on the achievement growth of their students). However, a major, large-scale evaluation of SIG by Mathematica showed no achievement benefits for schools that received SIG grants, compared to similar schools that did not. Ultimately, SIG spent more than $7 billion, an amount that we in Baltimore, at least, consider to be a lot of money. The tragedy, however, is not just the waste of so much money, but the dashing of so many hopes for meaningful improvement.

This is where the silk purse/sow’s ear analogy comes in. Each of the options among which SIG schools had to choose was composed of components that either lacked evidence of effectiveness or actually had evidence of ineffectiveness. If the components of each option are not known to be effective, then why would anyone expect a combination of them to be effective?

Evidence on school closure has found that this strategy diminishes student achievement for a few years, after which student performance returns to where it was before. Research on charter schools by CREDO (2013) has found an average effect size of zero for charters. The exception is “no-excuses” charters, such as KIPP and Success Academies, but these charters only accept students whose parents volunteer, not whole failing schools. Turnaround and transformation schools both require a change of principal, which introduces chaos and, as far as I know, has never been found to improve achievement. The same is true of replacing at least 50% of the teachers. Lots of chaos, no evidence of effectiveness. The other required elements of the popular “transformation” model have been found to have either no impact (e.g., benchmark assessments to inform teachers about progress; Inns et al., 2019), or small effects (e.g., lengthening the school day or year; Figlio et al., 2018). Most importantly, to my knowledge, no one ever did a randomized evaluation of the entire transformation model, with all components included. We did not find out what the joint effect was until the Mathematica study. Guess what? Sewing together swatches of sows’ ears did not produce a silk purse. With a tiny proportion of $7 billion, the Department of Education could have identified and tested out numerous well-researched, replicable programs and then offered SIG schools a choice among the ones that worked best. A selection of silk purses, all made from 100% pure silk. Doesn’t that sound like a better idea?

In later blogs I’ll say more about how the federal government could ensure the success of educational initiatives by ensuring that schools have access to federal resources to adopt and implement proven programs designed to accomplish the goals of the legislation.

References

Figlio, D., Holden, K. L., & Ozek, U. (2018). Do students benefit from longer school days? Regression discontinuity evidence from Florida’s additional hour of literacy instruction. Economics of Education Review, 67, 171-183.

Inns, A., Lake, C., Pellegrini, M., & Slavin, R. (2019). A synthesis of quantitative research on programs for struggling readers in elementary schools. Available at www.bestevidence.org. Manuscript submitted for publication.

This blog was developed with support from the Laura and John Arnold Foundation. The views expressed here do not necessarily reflect those of the Foundation.

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