2. What is validity????
VALIDITY is an indication of how sound your research is. More specifically,
validity applies to both the design and the methods of your research.
Validity in data collection means that your findings truly represent the
phenomenon you are claiming to measure
Research validity in surveys relates to the extent at which the survey
measures right elements that need to be measured. In simple terms, validity
refers to how well an instrument as measures what it is intended to
measure.
In psychometrics, validity has a particular application known as test validity:
"the degree to which evidence and theory support the interpretations of
test scores“
3. Validity has been broadly defined as the extent to which a text measures
what it purports to measure
Validity is at the core of testing and assessment, as it legitimises the
content of the tests, meaning the information gained from the test
answers is relevant to the topic needed
Validity is an integrated evaluative judgement of the degree to which
empirical evidence and theoretical rationales support the adequacy and
appropriateness of inferences and actions speak based on test scores or
other modes of measurements.
Research validity in surveys relates to the extent at which the survey
measures right elements that need to be measured Research validity can
be divided into two groups internal and external
4. Internal validity refers to how the research findings match reality, it is
important to keep in mind that the validity is a unitary concept.
Internal validity refers to whether the effects observed in a study are due
to the manipulation of the independent variable and not some other
factor. In-other-words there is a causal relationship between the
independent and dependent variable.
Internal validity can be improved by controlling extraneous variables, using
standardized instructions, counter balancing, and eliminating demand
characteristics and investigator effects.
INTERNAL VALIDITY
5. Factors affect internal validity
Subject variability
Size of subject population
Time given for the data collection or experimental treatment
History
Attrition
Maturation
Instrument/task sensitivity
6. EXTERNAL VALIDITY
External validity refers to the extent to which the results of a study can be
generalized to other settings (ecological validity), other people
(population validity) and over time (historical validity).
External validity can be improved by setting experiments in a more
natural setting and using random sampling to select participants.
EXTERNAL VALIDITY is the extent to which you can generalize your
findings to a larger group or other contexts. If your research lacks
external validity, the findings cannot be applied to contexts other than the
one in which you carried out your research. For example, if the subjects
are all males from one ethnic group, your findings might not apply to
females or other ethnic groups
7. Factors affect external validity
Population characteristics (subjects)
Interaction of subject selection and research
Descriptive explicitness of the independent variable
The effect of the research environment
Researcher or experimenter effects
Data collection methodology
The effect of time
8. Types of Validity
Content validity
Construct validity
Criterion related validity
Face validity
9. CONTENT VALIDITY
Content validity is the extent to which the elements within a
measurement procedure are relevant and representative of the construct
that they will be used to measure (Haynes et al., 1995). Establishing
content validity is a necessarily initial task in the construction of a new
measurement procedure (or revision of an existing one)
Content validity evidence involves the degree to which the content of
the test matches a content domain associated with the construct.
When constructing any test or questionnaire, the items should be
representative of the domain to be measured. For example, a spelling
test containing only the names of professional footballers would be of
poor content validity as a general purpose of spelling.
10. Mainly used in clinical psychology, measures an assessment on how well
it encompasses the entire part of personality or symptoms it is testing for,
and requires authorities to validate that these ‘parts’ make up the whole
picture of what an illness, etc. is.
Covers a representative sample of the behavior domain to be measured"
Content Validity (also known as logical validity) refers to the extent to
which a measure represents all facets of the construct (e.g. personality,
ability) being measured.
Content validity is most often addressed in academic and vocational
testing, where test items need to reflect the knowledge actually required
for a given topic area (e.g., history) or job skill (e.g., accounting).
In clinical settings, content validity refers to the correspondence between
test items and the symptom content of a syndrome.
11. Content validity is qualitative in nature, and asks whether a specific
element enhances or detracts from a test or research program
12. CRITERION-RELATED VALIDITY
Criterion or concrete validity is the extent to which a measure is related to an outcome.
Criterion validity is often divided into concurrent and predictive validity.
Concurrent validity refers to a comparison between the measure in question and an
outcome assessed at the same time.
Predictive validity compares the measure in question with an outcome assessed at a later
time.
Concurrent validity should not be used as a substitute for predictive validity without an
appropriate supporting rationale."
13. CONCURRENT VALIDITY
This is the degree to which a test corresponds to an external criterion that
is known concurrently (i.e. occurring at the same time). If the new test is
validated by a comparison with a currently existing criterion, we have
concurrent validity. Very often, a new IQ or personality test might be
compared with an older but similar test known to have good validity
already.
14. PREDICTIVE VALIDITY
This is the degree to which a test accurately predicts a criterion that will occur
in the future. For example, a prediction may be made on the basis of a new
intelligence test, that high scorers at age 12 will be more likely to obtain
university degrees several years later. If the prediction is born out then the
test has predictive validity.
Refers to the degree to which the operationalization can predict (or correlate
with) other measures of the same construct that are measured at some time
in the future. Again, with the selection test example, this would mean that the
tests are administered to applicants, all applicants are hired, their
performance is reviewed at a later time, and then their scores on the two
measures are correlated.
This is also when measurement predicts a relationship between what is
measured and something else. predicting whether or not the other thing will
happen in the future. High correlation between ex-ante predicted and ex-
post actual outcomes is the strongest proof of validity.
15. Criterion validity reflects the use of a criterion a well-established
measurement procedure - to create a new measurement procedure to
measure the construct you are interested in.
The criterion and the new measurement procedure must be theoretically
related. The measurement procedures could include a range of research
methods (eg-surveys, structured observation, or structured interviews, etc.
Criterion validity is the data that demonstrates that the scores on a test
related to some defined measure of interest.
For example score on a college entrance are planned to be used to
predictors of college Performance. The criterion measure of interest is then
some measure of college performance.
Criterion related validity can be seen by the strength of the relationship
between scores on the college entrance exam and the chosen criterion.
16. The test can be validated against as many criteria as there are specific uses for it they are
Academic achievement-
One of the most frequently used in criteria in validating intelligence tests is
done indicator of academic achievement. Specific indices used are school
grades achievement test scores promotion and graduation records
performance jn specialized training-this Can criterion that is commonly
used in the development of special aptitude test.
Job performance-one criterion that has been used in the validate of
general intelligence as well as personality tests and special aptitude test is
based on the following records of job performance.
17. psychiatric diagnosis
This criterion has been used as a source and evidence of test validity mainly
personality tests
Ratings
Those ratings made by school teachers job supervisor school counsellor,
come workers classmates fellow club members and other members of other
groups of associated are commonly used as criterion categories.
correlation between a new test and previously available tests.
A new test that is shortened or simplified version of a project a previously
available test can be measured against the criterion of the older test.
18. CONSTRUCT VALIDITY
Construct validity was invented by Cornball and Meehl (1955). This type of
validity refers to the extent to which a test captures a specific theoretical
construct or trait, and it overlaps with some of the other aspects of
validity
Construct validity does not concern the simple, factual question of
whether a test measures an attribute. Instead it is about the complex
question of whether test score interpretations are consistent with a
nomological network involving theoretical and observational terms
(Cronbach & Meehl, 1955).
Correlations with other scales will provide useful information on a test’s
construct validity
19. Construct validity is "the degree to which a test measures what it claims, or
purports, to be measuring.
Modern validity theory defines construct validity as the overarching
concern of validity research, subsuming all other types of There are a
number of different measures that can be used to validate tests, one of
which is construct validity.
Construct validity is used to determine how well a test measures what it is
supposed to measure.
Construct validity is usually verified by comparing the test to other tests
that measure similar qualities to see how highly correlated the two
measures are
20. Construct validity is essential to the perceived overall validity of the test.
Construct validity is particularly important in the social
sciences, psychology, psychometrics and language studies.
Construct Validity is the extent to which a test measures some established
construct or trait. Such constructs might be mechanical, verbal or spatial
ability, emotional stability or intelligence. Correlations with other scales will
provide useful information on a test’s construct validity
There is no single method of determining the construct validity of a test.
Instead, different methods and approaches are combined to present the
overall construct validity of a test. For example, factor analysis and
correlational methods can be used.
21. FACE VALIDITY
This is the least sophisticated measure of validity. Face validity is simply
whether the test appears (at face value) to measure what it claims to.
Face validity is the extent to which a test is subjectively viewed as covering
the concept it purports to measure. It refers to the transparency or
relevance of a test as it appears to test participants.
Face validity refers to the degree to which an assessment or test
subjectively appears to measure the variable or construct that it is
supposed to measure. In other words, face validity is when an assessment
or test appears to do what it claims to
22. For instance, if a test is prepared to measure whether students can perform
multiplication, and the people to whom it is shown all agree that it looks
like a good test of multiplication ability, this demonstrates face validity of
the test.
Face validity is often contrasted with content validity and construct validity
Face validity, also called logical validity, is a simple form of validity where
you apply a superficial and subjective assessment of whether or not your
study or test measures what it is supposed to measure
23. A direct measurement of face validity is obtained by asking people to rate
the validity of a test as it appears to them. This rater could use a likert scale
to assess face validity. For example:
- the test is extremely suitable for a given purpose
- the test is very suitable for that purpose;
- the test is adequate
- the test is inadequate
- the test is irrelevant and therefore unsuitable.
It is important to select suitable people to rate a test (e.g. questionnaire,
interview, IQ test etc.).
24. Having face validity does not mean that a test really measures what the
researcher intends to measure, but only in the judgment of raters that it
appears to do so. Consequently it is a crude and basic measure of validity.
