PSYCH 303 Chapter 5: Identifying Good Measures, Part III

16 views2 pages
9 Feb 2017
School
Department
Course

For unlimited access to Textbook Notes, a Class+ subscription is required.

Chapter 5: Identifying Good Measures
Validity of measurement- does it measure what it is supposed to measure?
Measurement validity of abstract constructs
Construct validity is important in psychological research, especially when a construct is
not directly observable
But how can we know if indirect operational measures of a construct are really
measuring happiness, for example, or something else?
Face validity and content validity- does it look like a good measure?
A measure has face validity to the extent that it appears to experts to be a plausible
measure of the variable in question
Face validity is a subject judgement: if it looks as if it should be a good measure, it
have face validity
To measure content validity, a measure must capture all parts of a a defined construct
Content validity also involves subjective judgment about a measure
Criterion validity- does it correlate with key behaviors?
Correlational evidence for criterion validity
Criterion validity values whether the measure under consideration is related to a
concrete outcome, such as behavior, that it should be related to, according to the
theory being tested
The behavioral criteria provided by criterion validity provide excellent evidence for
construct validity
No matter what type of operationalization is being used, if it is a good measure of its
construct, it should correlate with a criteria behavior or outcome that is related to that
construct
Known-groups evidence for criterion validity
Although evidence for criterion validity is commonly represented with correlation
coefficients, known-groups paradigm can be used to gather evidence for criterion
validity
Involves researchers seeing whether scores on the measure can discriminate among a
set of groups who behavior is already well understood
Good example is a lie detector, as it records a set of physiological measures (such as
skin conductance and heart rate) whose levels are suppose to indicate which of a
person’s statements are truthful and which are lies
The physiological measures should be elevated only for the lies, not for the true
statements
Can also be used to validate self-report measures
Convergent validity and discrimination validity- does the pattern make sense
Convergent validity
Measure correlates more strongly with other measures of the same constructs
Discrimination/divergent validity
Measure correlates less strongly with measures of different constructs
What matters is that this correlation is weak, not that it is negative
The relationship between reliability and validity
The validity of a measure is not the same as its reliability
A measure (such as head circumference) can be extremely reliable but still may not be
valid for an intended case (as a measure of intelligence)
Although a measure may be less valid than it is reliable, it cannot be more valid than i is
reliable
Reliability has to do with how well a measure correlates with itself
Unlock document

This preview shows half of the first page of the document.
Unlock all 2 pages and 3 million more documents.

Already have an account? Log in

Get access

Grade+
$10 USD/m
Billed $120 USD annually
Homework Help
Class Notes
Textbook Notes
40 Verified Answers
Study Guides
1 Booster Class
Class+
$8 USD/m
Billed $96 USD annually
Homework Help
Class Notes
Textbook Notes
30 Verified Answers
Study Guides
1 Booster Class