Education Week - October 9, 2019 - 17

How
Predictive
Are Tests?
Exploring the causal link
between test scores
and future success
Getty

By Dan Goldhaber
& Umut Özek
GOLDHABER is the director
of the Center for Analysis
of Longitudinal Data
in Education Research
(CALDER) at the American
Institutes for Research and
the director of the Center for
Education Data & Research
(CEDR) at the University
of Washington. ÖZEK is a
principal researcher at the
American Institutes for
Research.

T

he use of standardized tests as a
measure of student success and
progress in school goes back
decades, with federal policies
and programs that mandated
yearly assessments as part of
state accountability systems
significantly accelerating this trend in the past 20
years. But the tide has turned sharply in recent years.
Parents, advocates, and researchers have
increasingly raised concerns about the role of
testing in education. The shift in people's attitudes
about the use of tests and about the consequences
of relying (or possibly over-relying) on test scores
for the purposes of both school and teacher
accountability raises the question: What can tests
tell us about the contributions of schools and
teachers to student success in the future?
We think it is important to ask this foundational
question: How much do we know about whether
there is a causal link between higher test scores and
success later in life? After all, that is the purpose of
education-preparing students to be successful in
the future. We explored this question and the role of
tests in a recently published article in Educational
Researcher. We conclude that any debate about
the use of test scores in educational accountability
should: (1) consider the significant evidence
connecting test scores to later life outcomes; (2) take
into account the difficulty of establishing causality
between test achievement and later life outcomes;
and (3) consider what alternative measures of
success are out there and how reliable they are.
It is certainly reasonable to argue that we should
hold schools and teachers accountable for the test
performance of their students, but we likely care a
whole lot more about tests if they reflect increased
learning in school that translates into future success.
There is a vast research literature linking test
scores and later life outcomes, such as educational
attainment, health, and earnings. These observed
correlations, however, do not necessarily reflect
causal effects of schools or teachers on later life

outcomes. Maybe students who do well on tests are
the same students who wake up early in the morning,
go to work on time, and work hard, and that's the
reason for their success, not necessarily what they
learned in school. Also, differences in test scores
could reflect differences in learning opportunities
outside of school, including the supportiveness of
families or the communities in which students live.
What we do know more definitively about the
causality of this relationship comes from a limited
number of studies that examine the effects of
different educational inputs (for example, schools,
teachers, classroom peers, special programs) on
both student test scores and later life outcomes. For
instance, if a study finds test-score impacts and adultoutcome impacts that are in the same direction, this
could be regarded as evidence that test scores (and
the learning they represent) have an impact on later
life outcomes.
Our view is that studies that might be considered
causal do tend to find alignment between effects
on test scores and later life outcomes. Perhaps the
most influential studies in this strand were published
in 2014 by Raj Chetty, John Friedman, and Jonah
Rockoff, who found that students who were assigned
to teachers deemed highly effective learned more as
measured by tests and also were more likely to have
better adult outcomes, such as attending college and
earning higher salaries.
Another study by Chetty and co-authors examines
the long-term effects of peer quality in kindergarten
(once again, as indicated by test scores) using the
Tennessee Student/Teacher Achievement Ratio
experiment. The 2011 study finds that students who
are assigned to classrooms with higher achieving
peers have higher college attendance rates and adult
earnings. Similarly, using that same Tennessee
STAR experiment, a study by Susan Dynarski and
colleagues that same year looks at the effects of
smaller classes in primary school and finds that the
test-score effects at the time of the experiment are
an excellent predictor of long-term improvements in
postsecondary outcomes.

It is also important to recognize that we might
not always expect test-score effects of educational
interventions to align with adult outcomes. It is easy
to make the case that interventions can improve
later life outcomes without affecting the cognitive
skills of children. Choice schools may, for instance,
have stronger pipelines into college, leading to better
college-going results while not affecting learning
and test results, but we don't know this conclusively.
Irrespective of one's views on the degree to which
tests predict later life outcomes, we need to think
carefully about what abandoning the use of test
scores altogether might mean for education policy
and practice. From a practical perspective, we can't
wait many years to get long-term measures of what
schools are contributing to students. This does not
mean that test scores ought to be the exclusive or
even primary short-term measures, but if one believes
in some form of educational accountability, it is
important to consider what alternative measures of
success are out there and how reliable they are.
Lessening the weight of tests in accountability
calculations is consistent with ESSA, but there
are concerns about how "gameable" many of the
alternative measures might be. And there is no
doubt that we know less empirically about the causal
connections between many of these alternative
measures and long-term student prospects.
For example, are students assigned to teachers
who get good classroom observation ratings likely
to have better future prospects? Perhaps, but there is
less evidence about this type of measure than there
is about test-based measures. And if we do not use
test scores in teacher evaluations at all, are we going
back to the era of teacher accountability when 99
percent of all teachers across the country were rated
satisfactory or better?
People clearly have strong feelings about the
worth of-and the harm done by-testing. But
whatever our personal feelings, we need to evaluate
the power of test scores to predict the outcomes
we want for our students and consider what the
alternatives might be. n

EDUCATION WEEK | October 9, 2019 | www.edweek.org/go/opinion | 17
http://www.edweek.org/go/opinion
Education Week - October 9, 2019

Table of Contents for the Digital Edition of Education Week - October 9, 2019
