1 | Page
PSYC 230 Research Methods Final Questions
and Answers
What measurement property does a nominal scale have? Is it a
numeric scale? Give an example. Ans: Nominal scale has property
of difference only. You use symbols to classify or categorize. An
example of this is the genre of music--classical, country, rock
What measurement properties does an ordinal scale have? Give an
example. What can you conclude based on an ordinal scale that
you can't conclude based on a nominal scale? How are ordinal
scales limited in terms of the information they provide? Ans:
Ordinal has properties of difference and magnitude. An example
of this is ranking different spellers in class from greatest to least.
You can conclude magnitude but you cannot conclude magnitude
on nominal scale. Ordinal scales are limited because distances on
scale may not indicate equal distances on dimension. *order
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, 2 | Page
What measurement properties do interval scales have? Give an
example. How are they more informative than ordinal scales? Ans:
Interval scales have difference, magnitude, and equal intervals. An
example of this is different temperatures. They are more
informative than ordinal scales because it has equal distance on
the scale and that shows equal dimension being measured.
What measurement properties do ratio scales have? Give an
example. What type of conclusion do ratio scales allow that no
other scale allows? Ans: Ratio scales have difference, magnitude,
equal intervals, and absolute zero point. It allows ratio conclusions
(proportions)
To obtain good measurements, our instrument must be reliable.
What does this mean? Ans: Reliability means that you can count
on it, there is consistency and stable scores of your measurement
instrument. If the measure is reliable, it means you know you are
measuring something
To obtain good measurements, our instrument must be valid. What
does this mean? Ans: Validity means you have an accuracy of
inference. It is the extent that your measurement procedure is
measuring what you think it is measuring and whether you have
© 2025 All rights reserved
, 3 | Page
interpreted your scores correctly. Am I measuring what I think I'm
measuring?
What is a reliability coefficient? Why do we want it to be strong
and positive? Ans: Reliability coefficient is a type of correlation
that indicates consistency. It should be strong and positive to
indicate strong consistency of relationship.
Why must a measure be reliable in order to be valid? Ans: The
measure has to be reliable because it has to measure something
and this something has to be what you actually think you are
measuring and not measuring something completely different.
Can a measure be reliable but not valid? Give an example. Ans: A
measure can be reliable but not valid. For example, a new weight
scale can say you are 501 Ib, 502 Ib and 501 Ib after you weighed
yourself 3 times. It is reliable because the scores are consistent but
it is not valid because you do not actually weigh 500 Ib, which
makes it wrong.
What is "test-retest reliability"? Give an example. Which statistic is
used to assess this? What sort of statistical outcome would
indicate high reliability? Ans: Test-retest reliability is the
consistency of scores over time. The same test is administered to
© 2025 All rights reserved
, 4 | Page
individuals two times to correlate the scores to determine
reliability. An example is if you administer a test to a group of
students and then a week later you give them the test again, you
would expect them to have similar results. The scores are
correlated and are given a test re-test coefficient. The closer the
test scores are to each other, the higher the coefficient will be.
What is "equivalent forms reliability"? Give an example. Ans:
Equivalent-forms reliability is the consistency of scores on two
versions of a test, each version of the test given to the same group
of individuals. For example, the SAT. The SAT comes in different
forms but if a student scores high on one version, they should still
score high on a second version.
What is "internal consistency"? Give an example. How is internal
consistency assessed? What number would indicate good internal
consistency? Ans: Internal consistency is the reliability or
consistency of a questionnaire. An example, research is conducted
on constructs such as learning. They administer a test that is
composed of multiple questions but all questions are related to
the same construct and all questions are correlated with each
other. The coefficient alpha is the statistic used to indicate level of
© 2025 All rights reserved
PSYC 230 Research Methods Final Questions
and Answers
What measurement property does a nominal scale have? Is it a
numeric scale? Give an example. Ans: Nominal scale has property
of difference only. You use symbols to classify or categorize. An
example of this is the genre of music--classical, country, rock
What measurement properties does an ordinal scale have? Give an
example. What can you conclude based on an ordinal scale that
you can't conclude based on a nominal scale? How are ordinal
scales limited in terms of the information they provide? Ans:
Ordinal has properties of difference and magnitude. An example
of this is ranking different spellers in class from greatest to least.
You can conclude magnitude but you cannot conclude magnitude
on nominal scale. Ordinal scales are limited because distances on
scale may not indicate equal distances on dimension. *order
© 2025 All rights reserved
, 2 | Page
What measurement properties do interval scales have? Give an
example. How are they more informative than ordinal scales? Ans:
Interval scales have difference, magnitude, and equal intervals. An
example of this is different temperatures. They are more
informative than ordinal scales because it has equal distance on
the scale and that shows equal dimension being measured.
What measurement properties do ratio scales have? Give an
example. What type of conclusion do ratio scales allow that no
other scale allows? Ans: Ratio scales have difference, magnitude,
equal intervals, and absolute zero point. It allows ratio conclusions
(proportions)
To obtain good measurements, our instrument must be reliable.
What does this mean? Ans: Reliability means that you can count
on it, there is consistency and stable scores of your measurement
instrument. If the measure is reliable, it means you know you are
measuring something
To obtain good measurements, our instrument must be valid. What
does this mean? Ans: Validity means you have an accuracy of
inference. It is the extent that your measurement procedure is
measuring what you think it is measuring and whether you have
© 2025 All rights reserved
, 3 | Page
interpreted your scores correctly. Am I measuring what I think I'm
measuring?
What is a reliability coefficient? Why do we want it to be strong
and positive? Ans: Reliability coefficient is a type of correlation
that indicates consistency. It should be strong and positive to
indicate strong consistency of relationship.
Why must a measure be reliable in order to be valid? Ans: The
measure has to be reliable because it has to measure something
and this something has to be what you actually think you are
measuring and not measuring something completely different.
Can a measure be reliable but not valid? Give an example. Ans: A
measure can be reliable but not valid. For example, a new weight
scale can say you are 501 Ib, 502 Ib and 501 Ib after you weighed
yourself 3 times. It is reliable because the scores are consistent but
it is not valid because you do not actually weigh 500 Ib, which
makes it wrong.
What is "test-retest reliability"? Give an example. Which statistic is
used to assess this? What sort of statistical outcome would
indicate high reliability? Ans: Test-retest reliability is the
consistency of scores over time. The same test is administered to
© 2025 All rights reserved
, 4 | Page
individuals two times to correlate the scores to determine
reliability. An example is if you administer a test to a group of
students and then a week later you give them the test again, you
would expect them to have similar results. The scores are
correlated and are given a test re-test coefficient. The closer the
test scores are to each other, the higher the coefficient will be.
What is "equivalent forms reliability"? Give an example. Ans:
Equivalent-forms reliability is the consistency of scores on two
versions of a test, each version of the test given to the same group
of individuals. For example, the SAT. The SAT comes in different
forms but if a student scores high on one version, they should still
score high on a second version.
What is "internal consistency"? Give an example. How is internal
consistency assessed? What number would indicate good internal
consistency? Ans: Internal consistency is the reliability or
consistency of a questionnaire. An example, research is conducted
on constructs such as learning. They administer a test that is
composed of multiple questions but all questions are related to
the same construct and all questions are correlated with each
other. The coefficient alpha is the statistic used to indicate level of
© 2025 All rights reserved
