PSYCHOMETRY
VALIDITY
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“
 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
 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
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
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
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
Types of Validity
 Content validity
 Construct validity
 Criterion related validity
 Face validity
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.
 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.
 Content validity is qualitative in nature, and asks whether a specific
element enhances or detracts from a test or research program
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."
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.
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.
 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.
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.
 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.
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
 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
 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.
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
 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
 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.).
 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.
VALIDITY

VALIDITY

  • 1.
  • 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 hasbeen 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 validityrefers 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 internalvalidity  Subject variability  Size of subject population  Time given for the data collection or experimental treatment  History  Attrition  Maturation  Instrument/task sensitivity
  • 6.
    EXTERNAL VALIDITY  Externalvalidity 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 externalvalidity  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  Contentvalidity 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 usedin 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 validityis qualitative in nature, and asks whether a specific element enhances or detracts from a test or research program
  • 12.
    CRITERION-RELATED VALIDITY  Criterionor 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  Thisis 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  Thisis 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 validityreflects 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 canbe 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 Thiscriterion 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  Constructvalidity 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 validityis "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 validityis 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  Thisis 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 directmeasurement 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 facevalidity 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.