Psychometricians, such as Catherine McClellan, above, use statistics to determine whether a test is reliable.
Catherine McClellan knows how
to ace the test. That's because she
Catherine is a psychometrician. Like
many in this occupation, she designs, scores,
and analyzes data from exams.
Psychometrics is the science of measuring
psychological attributes, such as intelligence
or understanding. Tests are one way to assess
these intangible qualities. And psychometricians'
work ensures that each test is reliable
and that all test results are valid.
Specific job tasks vary with the type of
exam a psychometrician develops. Catherine
specializes in constructed response, a form of
testing that includes essays, art portfolios, and
other tests scored by humans. Other psychometricians
develop computer-scored exams.
When creating a test, psychometricians
might start by determining its basic structure:
which format to use, such as multiple-choice
or short-answer questions; how many questions
to ask; and the levels of difficulty of the
questions. Psychometricians then set the time
that will be allotted to take the test and make
decisions about scoring, such as how many
points to assign each question.
Like most psychometricians, Catherine
works with subject-matter experts to identify
what a test taker should know to be competent
in a particular discipline. The subject-matter
experts write questions and answers. Then,
everyone works together to make sure that the
test covers the right material and conforms
to the plan. For Catherine, collaborating with
these specialists is among the best parts of her
job. "It's endlessly fascinating because I get to
work with such a wide range of people," she
After new test content has been created,
psychometricians make sure that it is sound.
They might do this by conducting pilot trials—essentially, a test of the test. "We go out
and have people respond to the questions, and
then we analyze the data to see if the test is
working," says Catherine. Often, she says, a
good test points out differences in test takers'
Catherine spends a lot of time training
and overseeing the people who score the
exams, too, to be sure that they are grading
the exams fairly. One way she verifies that
raters are following the proper guidelines is to
randomly insert prescored tests into the group
of tests that a rater has to score. If the rater's
result matches the already assigned score, it's
an indication that he or she is following the
Psychometricians also analyze test results.
For example, they make scores comparable
from different versions of a test. And they use
score data to create reports or make recommendations—such as suggesting curriculum changes for improving student performance.
Many of the assessments that psychometricians
work on have significant implications
for test takers. Some psychometricians, for
example, design the licensure exams that give
teachers, lawyers, and others permission to
work in their fields. Other psychometricians
design instruments to evaluate factors ranging
from career interests to mental health, all of
which can affect decisions about the future.
Still other psychometricians, including
Catherine, create tests that measure student
aptitude or knowledge. Results of these tests
can influence a student's options for college
or a school's level of funding. "This is highstakes
stuff," says Catherine of her work.
"Sometimes, I think, ‘Wow, this changes
Helping to shape people's futures through
objective measurement requires lots of math
and statistics. For example, psychometricians
use math to calculate test takers' percentile
rankings. And they use statistics to determine
variances, correlations, and other measures of
a test's reliability.
Psychometricians need good communication
skills to explain the results of their work
to others. And attention to detail is essential.
Problem-solving and research skills also
are important. When choosing statistical
methods to assess a test's validity, for example,
Catherine might need to do significant
research. "If I don't like one method, I need to
research what to do to develop a better one,"
she says. "It rarely ever gets routine."
Most psychometricians work for testing
companies and for federal, state, or local government.
Other employers include hospitals,
mental health clinics, universities, and large
corporations. Catherine works for a nonprofit
testing company that produces and scores
well-known assessments such as the SAT Reasoning
Test, Advanced Placement (AP) exams,
and Graduate Record Examination (GRE).
The U.S. Bureau of Labor Statistics does
not collect employment or wage data specifically
on psychometricians. According to the
Psychometric Society, however, there are several
thousand of these workers in the United
States. The Society estimates that annual
wages can range from about $50,000 to
$100,000, although some workers earn more.
Workers' pay is high, in part, because of
the investment required to become proficient
in the field. Many psychometricians have a
Ph.D., usually in a subject such as educational
measurement, quantitative psychology, or statistics.
Others have a master's degree. There
are no undergraduate programs specifically in
psychometrics and only a few graduate-level
ones. Most people enter the discipline from a
related field, such as statistics, mathematics,
computer science, or psychology.
A former math teacher, Catherine first
learned about the occupation while earning
her master's degree in secondary math education.
"I really liked my measurement classes,
and one day my teacher told me, ‘You know,
you can get a degree in this.'" Catherine
completed her math education program and
then went on to get her Ph.D. in research and
evaluation methodology in education. She has
since worked on numerous projects, including
a nationwide assessment of U.S. students'
academic knowledge and experiences.
Catherine enjoys the role she now has in
improving education through exams. "I take
what I do very seriously," she says. "By helping
to make a good test, you feel like you can
change things for the better."