[The following is Daniel Koretz' preface to the book
Teachers, Performance Pay, and Accountability (What
Education Should Learn from Other Sectors), by Scott J.
Adams John Heywood Richard Rothstein (eds), ISBN:
1-932066-38-1. The book may be purchased ($14.50) from
the Economic Policy Institute at
http://mpower.mosaicprint.com/EPI/p-153-teachers-performance-pay-and-accountability-what-education-should-learn-from-other-sectors.aspx
-- moderator.]
Teachers, Performance Pay, and Accountability
What Education Should Learn From Other Sectors
05-14-09
May 2009 | An Econonic Policy Institute book
By Scott J. Adams, John S. Heywood & Richard Rothstein
Preface by Daniel Koretz
Series editors Sean P. Corcoran and Joydeep Roy
by Daniel Koretz
Accountability for students' test scores has become the
cornerstone of education policy in the United States.
State policies that rewarded or punished schools and
their staffs for test scores became commonplace in the
1990s. The No Child Left Behind (NCLB) act federalized
this approach and made it in some respects more
draconian. There is now growing interest in pay for
performance plans that would reward or punish
individual teachers rather than entire schools. This
volume is important reading for anyone interested in
that debate.
The rationale for this approach is deceptively simple.
Teachers are supposed to increase students' knowledge
and skills. Proponents argue that if we manage schools
as if they were private firms and reward and punish
teachers on the basis of how much students learn,
teachers will do better and students will learn more.
This straightforward rationale has led to similarly
simple policies in which scores on standardized tests
of a few subjects dominate accountability systems, to
the near exclusion of all other evidence of
performance.
It has become increasingly clear that this model is
overly simplistic, and that we will need to develop
more sophisticated accountability systems. However,
much of the debate-for example, arguments about the
reauthorization of NCLB-continues as if the current
approach were at its core reasonable and that the
system needs only relatively minor tinkering. To put
this debate on a sensible footing requires that we
confront three issues directly.
The first of these critically important issues,
addressed in the first section of this volume by Scott
Adams and John Heywood, is that the rationale for the
current approach misrepresents common practice in the
private sector. Pay for performance based on numerical
measures actually plays a relatively minor role in the
private sector. There are good reasons for this.
Economists working on incentives have pointed out for
some time that for many occupations (particularly,
professionals with complex roles), the available
objective measures are seriously incomplete indicators
of value to firms, and therefore, other measures,
including subjective evaluations, have to be added to
the mix.
And that points to the second issue, known as
Campbell's Law in the social sciences and Goodhart's
Law in economics. In large part because available
numerical measures are necessarily incomplete, holding
workers accountable for them-without countervailing
measures of other kinds-often leads to serious
distortions. Workers will often strive to produce what
is measured at the expense of what is not, even if what
is not measured is highly valuable to the firm. One
also often finds that employees "game" the system in
various ways that corrupt the performance measures, so
that they overstate production even with respect to the
goals that are measured. Richard Rothstein's section in
this volume shows the ubiquity of this problem and
illustrates many of the diverse and even inventive
forms it can take. Some distortions are inevitable,
even when an accountability system has net positive
effects that make it worth retaining. However, the net
effects can be negative, and the distortions are often
serious enough that they need to be addressed
regardless. To disregard this is to pay a great
disservice to the nation's children.
The third essential issue is score inflation-increases
in scores larger than the improvements in learning
warrant-which is the primary form Campbell's Law takes
in test-based accountability systems. Many educators
and policy makers insist that this is not a serious
problem. They are wrong: score inflation is real,
common, and sometimes very large.
Three basic mechanisms generate score inflation. The
first is gaming that increases aggregate scores by
changing the group of students tested-for example,
removing students from testing by being lax about
truancy or assigning students to special education. The
second, which is a consequence of our ill-advised and
unnecessary focus on a single cut score (the
"proficient" standard), is what many teachers call "the
bubble kids problem." Some teachers focus undue effort
on students near the cut while reducing their focus on
other students well below or above it, because only the
ones near the cut score offer the hope of improvement
in the numbers that count.
The third mechanism is preparing students for tests in
ways that inflates individual students' scores. This
mechanism is the least well understood and most
controversial, but it can be the most important of the
three, creating very large biases in scores. One often
hears the argument: "our test is aligned with
standards, and it measures important knowledge and
skills, so what can be wrong with teaching to it?" This
argument is baseless and shows a misunderstanding of
both testing and score inflation. Score inflation does
not require that the test contain unimportant material.
It arises because tests are necessarily small samples
of very large domains of achievement. In building a
test, one has to sample not only content, but task
formats, criteria for scoring, and so on. When this
sampling is somewhat predicable-as it almost always is-
teachers can emphasize the material most likely to
recur, at the expense of other material that is less
likely to be tested but that is nonetheless important.
The result is scores that overstate mastery of the
domain. The evidence is clear that this problem can be
very large. There is no space here to discuss this
further, but if you are not persuaded, I strongly urge
you to read Measuring Up: What Educational Testing
Really Tells Us, where I explain the basic mechanisms
by which this happens and show some of the evidence of
the severity of the problem.
My experience as a public school teacher, my years as
an educational researcher, and my time as a parent of
students in public schools have all persuaded me that
we need better accountability in schools. We won't
achieve that goal, however, by hiding our heads in the
sand. This volume will make an important contribution
to sensible debate about more effective approaches.
Daniel Koretz is the Henry Lee Shattuck Professor of
Education at the Harvard Graduate School of Education,
Harvard University, and is a member of the National
Academy of Education.
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