This document discusses validity and reliability in research tools. It defines validity as the degree to which a tool measures what it is intended to measure. There are several types of validity discussed, including face validity, content validity, criterion validity (predictive and concurrent validity), and construct validity. Reliability refers to the consistency and accuracy of a measurement and there are three main types: test-retest reliability, split-half reliability, and parallel forms reliability. The document provides examples and formulas for calculating different aspects of validity and reliability.

1. Subject: Nursing Research
Topic: Validity& Realibility
Prepared by:
Chandani M.Aparnathi
F.Y.M.Sc. Nursing
Roll No:02

2. VALIDITY OF RESEARCH
TOOL
INTRODUCTION
• Validity of an instrument refers to the
degree to which an instrument
measures what it is supposed to be
measuring
• EXAMPLE: a temperature measuring
instrument is supposed to measure
only the temperature; it cannot be
considered a valid instrument if it
measures an attribute other than
temperature.

3. DEFINITIONS
 “Validity refers to an instrument or test
actually testing what is supposed to be
testing.”
Treece and
Treece
 “Validity refers to the degree to which an
instrument measures what is supposed to be
measuring.” Pilot and Hungler
 “Validity is the appropriateness,meaning
fullness and usefulness of the
interference,made from the scoring of the
instrument.
American Psychological

5. TYPES
OF VALIDITY
FACE
VALIDITY
CONTENT
VALIDITY
CRITERIAN
VALIDITY
PREDICTIVE
VALIDITY
CONCURRENT
VALIDITY
CONSTRUCT
VALIDITY
INTERNAL AND
EXTERNAL
VALIDITY

6. 1) Face Validity:
 It is the extent to which the measurement
method appears “on its face” to measure
the construct of interest.
 EXAMPLE:
 People might have negative reactions to
an intelligence test that did not appear to
them to be measuring their intelligence.

7. 2) Content Validity:
 It is the extent to which the
measurement method covers the entire
range of relevant behaviours, thoughts,
and feelings that define the construct
being measured.
 EXAMPLE:
 A course exam has good content validity
if it covers all the material that students
are supposed to learn and poor content
validity if it does not.

8. 3) Criterion Validity
 It is the extent to which people ‘s
scores are correlated with other
variables or criteria that reflects
the same construct.
 EXAMPLE:
 An IQ test should correlated
positively with school performance.
 An occupational aptitude test
should correlate positively with
work performance.

9. a) Predictive Validity
 A new measure of self-esteem should
correlate positively with an old
established measure.
 When the criterion is something that will
happen or be assessed in the future,
this is called predictive validity.

10. b) Concurrent Validity
 When the criterion is something that is
happening or being assessed at the
same time as the construct of interest
,it is called concurrent validity.

11. 4) Construct Validity:
 Construct validity is basically assessing
how accurately your ideas and theories
have been translated into actual
procedure or measure.

12. 5) Internal and external Validity
 The term internal and external are
applied to validity in the experimental
situation.
 Internal validity: It is basically the
extent to which a study is free from flaws
and that any difference in a
measurement are due to an independent
variable and nothing else.
 External validity: It is the extent to
which the results of a research study can
be generalized to different situation,
different groups of people, different

13. REABILITY OF RESEARCH
TOOL
• Reliability is one of the important
characteristics of any test.
• It refers to the precision or accuracy of
the measurement of scope.
• Relibility refers to the stability of a test
measure or protocol.

14. Definition
 “Reliability is a major concern when a
psychological test is used to measure
some attributes or behaviour”
-Rosenthal
 “Reliability refers to the to the
consistency of scores obtained by the
same individuals when reexamined with
test on different occasions, or with
different sets of items ,or under other
variable examining conditions”

15. Types of Reliability
 Three important types
1) Test-Retest reliability
II) Splilt – half reliability
III)Parallel forms reliability

16. Test – Retest reliability
• In test – retest reliability the single
from of the test is administered twice
on the same sample with a reasonable
time gap.
• In this way two administration of the
same from of the two independent
sets of scores.
• The two sets, when corelated, give the
value of the reliability coefficient.

17. Test-Retest Reliability

18. CONTI…….
 Measure instrument at two times for
multiple persons.
 Compute correlation between the two
measures.
 Formula used to calculate reliability:

19. Split-half relibility
 Other name internal consistency
reliability
 It indicates the homogeneity of the test
 This method the test is divided into two
equal or nearly halves
 Common way of this test is the odd-even
method

20. CONTI….

21. CONTI…..
 Indicates that subjects score on some
trials consistently match their scores
on other trials.
 Formula used to calculate split half
reliability:

22. Parrallel - Forms Reliability
 This reliability various names such as,
a. Alternative – forms reliability
b. Equivalent – forms reliability
c. Comparable – forms reliability

23. CONTI…..
 The alternative forms technique to
estimate reliability is similar to the test
retest method, expect that different
measures of a behaviour are collected
at different times.
 If the correlation between the
alternative forms is low, it could
indicate that considerable
measurement error is
present,because two different scales
were used.

24. CONTI….

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