The document discusses validity and reliability in research. It defines validity as measuring what the research intends to measure and having truthful results. There are three types of validity: content, construct, and criterion-related. Reliability refers to consistency of results over time and accurately representing the population. It can be measured through test-retest, alternative forms, and split-half methods. Validity and reliability are both important but distinct concepts for assessing quality of research.

1. Presented by:
Surendra Poudel

2. VALIDITY
• “Validity refers to the truthfulness of findings. It
determines whether the research truly measures that
what it was intended to measure or how truthful the
research results are.”
• Validity refers to the credibility or believability of the
research. Are the findings genuine? Is hand
strength a valid measure of intelligence?

3. Valid measures should
satisfy three criteria
• Content Validity
• Construct Validity
• Criterion-Related Validity

4. 1. Content Validity
Content validity concerns the extent to which a
measure adequately represents all facets of
concept.
Validity access the following:
a. Does the instrumental seem like a reasonable
way to gain the desired information?
b. Does it seems well designed?
c. Is it good “operationalization” or “translation” of
the construct?

5. 2. Construct Validity
Construct validity is the extent to which a test
measures the concept or construct that it is intended
to measure.
Convergent and discriminate validity:
• Convergent validity refers to the degree to which
two measures of constructs that theoretically should
be related, are in fact related.
• In contrast discriminate validity tests whether
concepts or measurements that are supposed to be
unrelated are, in fact, unrelated

6. Three steps should follow to know whether
a piece of research has construct validity:
1. The theoretical relationship must be specified.
2. The empirical relationship between the measures of
the concept must be examined.
3. The empirical evidences must be interpret.

7. Criterion validity
Criterion 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 on the other hand, compares the
measure in question with an outcome assessed at
a later time.

8. RELIABILITY
• The extent to which results are consistent over time and an
accurate representation of the total population under study
is referred to as a reliability, and if the results of a study can
be reproduced under a similar methodology, then the
research instrument is considered to be reliable.
• Reliability means the consistency between measurements
in a series.

9. Methods of
Obtaining Reliability
1. Test -Related Reliability: same test is given to
the same people after a period of time
2. Alternative form Reliability: same test isnt given
instead two tests must be designed to measure
the same things.
3. Split-Half Reliability: it involves dividing the
total number of items into two groups and
computing a measures of similarity (calculating
correlation between two halves of an
instruments)

10. Relationship between
Reliability and Validity