In Education Myths I argued that we needed to rely on science rather than our direct experience to identify effective policies.  Our eyes can mislead us, while scientific evidence has the systematic rigor to guide us more accurately.

That’s true, but I am now more aware of the opposite failing — believing that we can resolve all policy disputes and identify the “right way” to educate all children solely by relying on science.  Science has its limits.  Science cannot adjudicate among the competing values that might attract us to one educational approach over another.  Science usually tells us about outcomes for the typical or average student and cannot easily tell us about what is most effective for individual students with diverse needs.  Science is slow and uncertain, while policy and practice decisions have to be made right now whether a consensus of scientific evidence exists or not.  We should rely on science when we can but we also need to be humble about what science can and can’t address.

I was thinking about this while reflecting on the Gates Foundation’s Measuring Effective Teachers Project.  The project is an ambitious $45 million enterprise to improve the stability of value-added measures while identifying effective practices that contribute to higher value-added performance.  These are worthy goals.  The project intends to advance those goals by administering two standardized tests to students in 8 different school systems, surveying the students, and videotaping classroom lessons.

The idea is to see if combining information from the tests, survey, and classroom observations could produce more stable measures of teacher contributions to learning than is possible by just using the state test.  And since they are observing classrooms and surveying students, they can also identify certain teacher practices and techniques that might be associated with greater improvement.  The Gates folks are using science to improve the measures of student progress and to identify what makes a more effective teacher.

This is a great use of science, but there are limits to what we can expect.  When identifying practices that are more effective, we have to remember that this is just more effective for the typical student.  Different practices may be more effective for different students.  In principle science could help address this also, but even this study, with 3,000 teachers, is not nearly large enough to produce a fine-grained analysis of what kind of approach is most effective for many different kinds of kids.

My fear is that the researchers, their foundation-backers, and most-importantly, the policymaker and educator consumers of the research are insensitive to these limitations of science.  I fear that the project will identify the “right” way to teach and then it will be used to enforce that right way on everyone, even though it is highly likely that there are different “right” ways for different kids.

We already have a taste of this from the preliminary report that Gates issued last month.  Following its release Vicki Phillips, the head of education at the Gates Foundation, told the New York Times: “Teaching to the test makes your students do worse on the tests.”  Science had produced its answer — teachers should stop teaching to the test, stop drill and kill, and stop test prep (which the Gates officials and reporters used as interchangeable terms).

Unfortunately, Vicki Phillips mis-read her own Foundation’s report.  On p. 34 the correlation between test prep and value-added is positive, not negative.  If the study shows any relationship between test prep and student progress, it is that test prep contributes to higher value-added.  Let’s leave aside the fact that these were simply a series of pairwise correlations and not the sort of multivariate analysis that you would expect if you were really trying to identify effective teaching practices.  Vicki Phillips was just plain wrong in what she said.  Even worse, despite having the error pointed out, neither the Gates Foundation nor the New York Times has considered it worthwhile to post a public  correction.  Science says what I say it says.

And this is the greatest danger of a lack of humility in the application of science to public policy.  Science can be corrupted so that it simply becomes a shield disguising the policy preferences of those in authority.  How many times have you heard a school official justify a particular policy by saying that it is supported by research when in fact no such research exists?  This (mis)use of science is a way for authority figures to tell their critics, “shut up!”

But even if the Gates report had conducted multivariate analyses on effective teaching practices and even if Vicki Phillips could accurately describe the results of those analyses, the Gates project of using science to identify the “best” practices is doomed to failure.  The very nature of education is that difference techniques are more effective in different kinds of situations for different kinds of kids.  Science can identify the best approach for the average student but it cannot identify the best approach for each individual student.  And if students are highly varied in their needs, which I believe they are, this is a major limitation.

But as the Gates Foundation pushes national standards with new national tests, they seem inclined to impose the “best” practices that science identified on all students.  The combination of Gates building a national infrastructure for driving educator behavior while launching a gigantic scientific effort to identify the best practices is worrisome.

There is nothing wrong with using science to inform local practice.  But science needs markets to keep it honest.  If competing educators can be informed by science, then they can pick among competing claims about what science tells us.  And they can learn from their experience whether the practices that are recommended for the typical student by science work in the particular circumstances in which they are operating.

But if the science of best educator practice is combined with a national infrastructure of standards and testing, then local actors cannot adjudicate among competing claims about what science says.  What the central authorities decide science says will be infused in the national standards and tests and all must adhere to that vision if they wish to excel along these centralized criteria.  Even if the central authority completely misunderstands what science has to say, we will all have to accept that interpretation.

I don’t mean to be overly alarmist.  Gates has a lot of sensible people working for them and there are many barriers remaining before we fully implement national standards and testing.  My concern is that the Gates Foundation is being informed by an incorrect theory of reform.  Reform does not come from science identifying the right thing to do and then a centralized authority imposing that right thing on everyone.  Progress comes from decentralized decision-makers having the freedom and motivation to choose among competing claims about what is right according to science.

– Jay P. Greene

Addendum

I just wanted to add a few thoughts to my post yesterday.  Readers may be wondering what is wrong with using science to identify the best educational practices and then implementing those best practices.  If they are best, why wouldn’t we want to do them?

Let me answer by analogy.  We could use science to identify where we could get the highest return on capital.  If science can tell us where the highest returns can be found, why would we want to let markets allocate capital and potentially make a lot of mistakes?  Government could just use science and avoid all of those errors by making sure capital went to where it could best be used.

Of course, we tried this approach in the Soviet Union and it failed miserably.  The primary problem is that science is always uncertain and susceptible to corruption.  We can run models to measure returns on capital, but we have uncertainty about the models and we have uncertainty about the future.  Markets provide a reality test to scientific models by allowing us to choose among competing models and experience the consequences of choosing wisely or not.  Science can advise us, but only choice, freedom, and experience permit us to benefit from what science has to offer.

And even more dangerous is that in the absence of choice and competition among scientific models, authorities will allow their own interests or preferences to distort what they claim science has to say.  For an excellent example of this, check out the story of Lysenko and Soviet research on genetics.  For decades Soviet science was compelled to believe that environmental influences could be inherited.

Science facilitates progress through the crucible of market tests.  Science without markets facilitates stronger authoritarianism.