CDC Told to Avoid Use of “Evidence-Based”: Is the Earth Flat Again?

In this blog series, I generally try to stay non-partisan, avoiding issues that, though important, do not relate to evidence-based reform in education. However, the current administration has just crossed that line.

In a December 16 article in the Washington Post, Lena Sun and Juliet Eilperin reported that the Trump Administration has prohibited employees of the Centers for Disease Control and Prevention (CDC) from using seven words or phrases in their reports. Two of these are “evidence-based” and “science-based.” Admittedly, this relates to health, not education, but who could imagine that education will not be next?

I’m not sure exactly why “evidence-based” and “science-based” are included among a set of banned words that otherwise consist of words such as “fetus,” “transgender,” and “diversity” that have more obvious political overtones. The banning of “evidence-based” and “science-based” is particularly upsetting because evidence, especially in medicine, has up to now been such a non-partisan, good-government concept. Ultimately, Republicans and Democrats and their family members and friends get sick or injured, or want to prevent disease, and perhaps as a result, evidence-based health care has been popular on both sides of the aisle. In education, Republican House Speaker Paul Ryan and Democratic Senator Patty Murray have worked together as forceful advocates for evidence-based reform, as have many others. George W. Bush and Barak Obama both took personal and proactive roles in advancing evidence in education.

You have to go back a long time to find governments banning evidence itself. Perhaps you have to go back to Pope Paul V, whose Cardinal Bellarmine ordered Galileo in 1615 to: “…abandon completely the opinion that the sun stands still at the center of the world and the Earth moves…”

In fear for his life, Galileo agreed, but in 1633, Galileo was accused of breaking his promise. He was threatened with torture, and had to agree again to the Pope’s demand. He was placed under house arrest for the rest of his life.

After his 1633 banishment, Galileo was said to have muttered, “E pur si muove” (And yet it moves). If he did (historians doubt it), he was expressing defiance, but also a key principle of science: “Proven principles remain true even if we are no longer allowed to speak of them.”

The CDC officials were offered a new formulation to use instead of “evidence-based” and “science-based.” It was: “CDC bases its recommendations on science in consideration with community standards and wishes.”

This is of course the antithesis of evidence or science. Does the Earth circle the sun in some states or counties, but it’s the other way around in others? Who decides which scientific principles apply in a given location? Does objective science have any role at all or are every community’s beliefs as valid as every other’s? Adopting the ban would hold back research and applications of settled research, harming millions of potential beneficiaries and making the U.S. a laughingstock among advanced nations. Banning the words “evidence-based” and “science-based” will not change scientific reality. Yet it will perhaps slow down funding for research and dissemination of proven treatments, and that would be disastrous, both in medicine and in education. I hope and expect that scientists in both fields will continue to find the truth and make it known whatever the consequences, and that our leaders of both parties see the folly of this action and reverse it immediately.

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.



On Motivation

Once upon a time there was a man standing on a city street selling pencils from a tin cup. An old friend came by and recognized him.

“Hank!” said his friend. “What happened to you? Didn’t you have a big job at the Acme Dog Food Company?”

Hank hung his head. “I did,” he said mournfully. “I was its chief scientist. But it closed down, and it was all my fault!”

“What happened?” asked his friend.

“We decided to make the best dog food ever. We got together the top experts in dog nutrition in the whole world to find out what dogs really need. We put in the very best ingredients, no matter what they cost.”

“That sounds wonderful!” exclaimed the friend.

“It sounded great,” sighed Hank, “but the darned dogs wouldn’t eat it!”

In educational development, research, and dissemination, I think we often make the mistake made by the mythical Acme Dog Food Company. We create instructional materials and software completely in accord with everything the experts recommend. Today, for example, someone might make a program that is aligned with the Common Core or other college- and career-readiness standards, that uses personalization and authentic problem solving, and so on. Not that there is anything wrong with these concepts, but are they enough?

The key factor, I’d argue, is motivation. No matter how nutritious our instruction is, it has to appeal to the kids. In a review of secondary reading programs my colleagues and I wrote recently (, most of the programs evaluated were 100% in accord with what the experts suggest. In particular, most of them emphasized the teaching of metacognitive skills, which has long been the touchstone for secondary reading, and many also provided an extra instructional period every day, in accord with the popular emphasis on extra-time strategies.

However, the approaches that made the biggest differences in reading outcomes were not those that provided extra time. They included small-group or individual tutoring approaches, cooperative learning, BARR (a program focusing on building relationships between teachers and students), and a few technology approaches. The successful approaches usually included metacognitive skills, but so did many programs that did not show positive outcomes.

What united the successful strategies is that they all get to the head through the heart.

Tutoring allows total personalization of instruction, but it also lets tutors and students build personal, close relationships. BARR (Building Assets, Reducing Risks) is all about building personal relationships. Cooperative learning focuses on building relationships among students, and adding an element of fun and engagement to daily lessons. Some technology programs are also good at making lessons fun and engaging.

I can’t say for sure that these were the factors that made the difference in learning outcomes, but it seems likely. I’d never say that instructional content and strategies don’t matter. They do. But the very best teaching methods with the very best content are unlikely to enhance learning very much unless they make the kids eager to learn.

Why the What Works Clearinghouse Matters

In 1962, the most important breakthrough in modern medicine took place. It was not a drug, not a device, not a procedure. It did not immediately save a single life, or cure a single person of disease. But it profoundly changed medicine worldwide, and led to the rapid progress in all of medicine that we have come to take for granted.

This medical miracle was a law, passed in the U.S. Congress, called the Kefauver-Harris Drug Act. It required that drugs sold in the U.S. be proven safe and effective, in high-quality randomized experiments. This law was introduced by Senator Estes Kefauver of Tennessee, largely in response to the thalidomide disaster, when a widely used drug was found to produce disastrous birth defects.

From the moment the Act was passed, medical research changed utterly. The number of randomized experiments shot up. There are still errors and debates and misplaced enthusiasm, but the progress that has made in every area of medicine is undeniable. Today, it is unthinkable in medicine that any drug would be widely sold if it has not been proven to work. Even though Kefauver-Harris itself only applies to the U.S., all advanced countries now have similar laws requiring rigorous evidence of safety and effectiveness of medicines.

One of the ways the Kefauver-Harris Act made its impact was through reviews and publications of research on the evidence supporting the safety and efficacy of medicines. It’s no good having a law requiring strong evidence if only experts know what the evidence is. Many federal programs have sprung up over the years to review the evidence of what works and communicate it to front-line practitioners.

In education, we are belatedly going through our own evidence revolution. Since 2002, the function of communicating the findings of rigorous research in education has mostly been fulfilled by the What Works Clearinghouse (WWC), a website maintained by the U.S. Department of Education’s Institute of Education Sciences (IES). The existence of the WWC has been enormously beneficial. In addition to reviewing the evidence base for educational programs, the WWC’s standards set norms for research. No funder and no researcher wants to invest resources in a study they know the WWC will not accept.

In 2015, education finally had what may be its own Kefauver-Harris moment. This was the passage by the U.S. Congress of the Every Student Succeeds Act (ESSA), which contains specific definitions of strong, moderate, and promising levels of evidence. For certain purposes, especially for school improvement funding for very low-achieving schools, schools must use programs that meet ESSA evidence standards. For others, schools or districts can receive bonus points on grant applications if they use proven programs.

ESSA raises the stakes for evidence in education, and therefore should have raised the stakes for the WWC. If the government itself now requires or incentivizes the use of proven programs, then shouldn’t the government provide information on what individual programs meet those standards?

Yet several months after ESSA was passed, IES announced that the WWC would not be revised to align itself with ESSA evidence standards. This puts educators, and the government itself, in a bind. What if ESSA and WWC conflict? The ESSA standards are in law, so they must prevail over the WWC. Yet the WWC has a website, and ESSA does not. If WWC standards and ESSA standards were identical, or nearly so, this would not be a problem. But in fact they are very far apart.

Anticipating this situation, my colleagues and I at Johns Hopkins University created a new website, It launched in February, 2017, including elementary and secondary reading and math. We are now adding other subjects and grade levels.

In creating our website, we draw from the WWC every day, and in particular use a new Individual Study Database (ISD) that contains information on all of the evaluations the WWC has ever accepted.

The ISD is a useful tool for us, but it has made it relatively easy to ask and answer questions about the WWC itself, and the answers are troubling. We’ve found that almost half of the WWC outcomes rated “positive” or “potentially positive” are not even statistically significant. We have found that measures made by researchers or developers produce effect sizes more than three times those that are independent, yet they are fully accepted by the WWC.

As reported in a recent blog, we’ve discovered that the WWC is very, very slow to add new studies to its main “Find What Works” site. The WWC science topic is not seeking or accepting new studies (“This area is currently inactive and not conducting reviews”). Character education, dropout prevention, and English Language Learners are also inactive. How does this make any sense?

Over the next couple of months, starting in January, I will be releasing a series of blogs sharing what we have been finding out about the WWC. My hope in this is that we can help create a dialogue that will lead the WWC to reconsider many of its core policies and practices. I’m doing this not to compete or conflict with the WWC, but to improve it. If evidence is to have a major role in education policy, government has to help educators and policy makers make good choices. That is what the WWC should be doing, and I still believe it is possible.

The WWC matters, or should matter, because it expresses government’s commitment to evidence, and evidence-based reform. But it can only be a force for good if it is right, timely, accessible, comprehensible, and aligned with other government initiatives. I hope my upcoming blogs will be read in the spirit in which they were written, with hopes of helping the WWC do a better job of communicating evidence to educators eager to help young people succeed in our schools.


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.