QUALITATIVE AND QUANTITATIVE MEASUREMENT
about pay and household tasks. They ignore the
other areas (intellectual pursuits, politics, authority
relations, and other aspects of work and family). For
a content-valid measure, I must either expand the
measure or narrow the definition.^11
- Criterion validityuses some standard or
criterion to indicate a construct accurately. The va-
lidity of an indicator is verified by comparing it with
another measure of the same construct in which a
researcher has confidence. The two subtypes of this
type of validity are concurrent and predictive.^12
To h ave concurrent validity, we need to asso-
ciate an indicator with a preexisting indicator that
we already judge to be valid (i.e., it has face valid-
ity). For example, we create a new test to measure
intelligence. For it to be concurrently valid, it should
be highly associated with existing IQ tests (assum-
ing the same definition of intelligence is used). This
means that most people who score high on the old
measure should also score high on the new one, and
vice versa. The two measures may not be perfectly
associated, but if they measure the same or a simi-
lar construct, it is logical for them to yield similar
results.
Criterion validity by which an indicator pre-
dicts future events that are logically related to a con-
struct is called predictive validity. It cannot be used
for all measures. The measure and the action pre-
dicted must be distinct from but indicate the same
construct. Predictive measurement validity should
not be confused with prediction in hypothesis test-
ing in which one variable predicts a different vari-
able in the future. For example, the Scholastic
Assessment Test (SAT) that many U.S. high school
students take measures scholastic aptitude: the abil-
ity of a student to perform in college. If the SAT has
high predictive validity, students who achieve high
SAT scores will subsequently do well in college. If
students with high scores perform at the same level
as students with average or low scores, the SAT has
low predictive validity.
Another way to test predictive validity is to se-
lect a group of people who have specific character-
istics and predict how they will score (very high or
very low) vis-à-vis the construct. For example, I cre-
ate a measure of political conservatism. I predict
that members of conservative groups (e.g., John
Birch Society, Conservative Caucus, Daughters of
the American Revolution, Moral Majority) will
score high on it whereas members of liberal groups
(e.g., Democratic Socialists, People for the Ameri-
can Way, Americans for Democratic Action) will
score low. I “validate” it by pilot-testing it on mem-
bers of the groups. It can then be used as a measure
of political conservatism for the public.
- Construct validityis for measures with
multiple indicators. It addresses this question: If the
measure is valid, do the various indicators operate
in a consistent manner? It requires a definition with
clearly specified conceptual boundaries. The two
types of construct validity are convergent and dis-
criminant.
Convergent validityapplies when multiple in-
dicators converge or are associated with one an-
other. It means that multiple measures of the same
construct hang together or operate in similar ways.
For example, I measure the construct “education”
by asking people how much education they have
completed, looking up school records, and asking
the people to complete a test of school knowledge.
If the measures do not converge (i.e., people who
claim to have a college degree but have no records
of attending college or those with college degrees
perform no better than high school dropouts on my
tests), my measure has weak convergent validity,
and I should not combine all three indicators into
one measure.
Concurrent validity Measurement validity that re-
lies on a preexisting and already accepted measure to
verify the indicator of a construct.
Predictive validity Measurement validity that relies
on the occurrence of a future event or behavior that is
logically consistent to verify the indicator of a construct.
Convergent validity A type of measurement valid-
ity for multiple indicators based on the idea that indi-
cators of one construct will act alike or converge.
Construct validity A type of measurement validity
that uses multiple indicators and has two subtypes:
how well the indicators of one construct converge or
how well the indicators of different constructs diverge.
Criterion validity Measurement validity that relies
on some independent, outside verification.
