Chapter – 6
Reliability, Validity &
Norms
, Chapter – 6
Reliability, Validity & Norms
6.1.0 Introduction
6.2.0 Reliability
6.2.1 Types of Reliability
6.2.2 Reliability of the Present Inventory
(A) Test-Retest method
(B) Split – Half method
(C) Cronbach’s alpha (α)
6.2.3 Summary of the reliability
6.3.0 Validity
6.3.1 Types of Validity
6.3.2 Validity of the present Inventory
(A) Face Validity
(B) Construct Validity
6.3.3 Summary of the Validity
6.4.0 Norms
6.4.1 Types of Norms
6.4.2 Norms for the present SRL Inventory
6.5.0 Test Manual
6.5.1 Pre-conditions for administering the SRL inventory
6.5.2 Administering the SRL Inventory
6.5.3 Scoring the responses
6.5.4 Conversion of Raw scores into PR and T score
6.5.5 Qualitative Interpretation of PR
6.6.0 Conclusion
, Chapter -6
Reliability, Validity & Norms
6.1.0 Introduction :
In the previous chapter, we discussed and elaborated on the process of tool
construction.
The main purpose of any tool is to obtain data which is reliable and valid so
the researcher can read the prevalent situation accurately and arrive at some conclusions
to offer some suggestions. However, no tool is perfectly reliable or valid. So, it should be
accompanied by a statement of its reliability and validity. Here, in this chapter, the
estimation of reliability and validity of the inventory constructed are discussed along
with its norms in detail.
6.2.0 Reliability :
Reliability of a test pertains to reliable measurement which means that the
measurement is accurate and free from any sort of error. Reliability is one of the most
essential characteristic of a test. If a test gives same result on different occasions, it is
said to be reliable. So Reliability means consistency of the test result, internal
consistency and consistency of results over a period of time.
According to Anastasi and Ubrina (1982)1
“Reliability referes to the consistency of scores obtained by the
same persons when they are re-examined with the same test on
different occasions, or with different sets of equivalent items, or
under other variable examining conditions.”
Reliability is defined mathematically as the ratio of the variation of the true
score and the variation of the observed score. Or, equivalently, one minus the ratio of the
variation of the error score and the variation of the observed score.
r . is the symbol for the reliability of the observed score x, and x2,
T2 and E2 are the variances of the measured, true and error scores respectively. However,
there is no direct way to observe or calculate the true score, so a variety of methods are
used to estimate the reliability of a test.
84
Reliability, Validity &
Norms
, Chapter – 6
Reliability, Validity & Norms
6.1.0 Introduction
6.2.0 Reliability
6.2.1 Types of Reliability
6.2.2 Reliability of the Present Inventory
(A) Test-Retest method
(B) Split – Half method
(C) Cronbach’s alpha (α)
6.2.3 Summary of the reliability
6.3.0 Validity
6.3.1 Types of Validity
6.3.2 Validity of the present Inventory
(A) Face Validity
(B) Construct Validity
6.3.3 Summary of the Validity
6.4.0 Norms
6.4.1 Types of Norms
6.4.2 Norms for the present SRL Inventory
6.5.0 Test Manual
6.5.1 Pre-conditions for administering the SRL inventory
6.5.2 Administering the SRL Inventory
6.5.3 Scoring the responses
6.5.4 Conversion of Raw scores into PR and T score
6.5.5 Qualitative Interpretation of PR
6.6.0 Conclusion
, Chapter -6
Reliability, Validity & Norms
6.1.0 Introduction :
In the previous chapter, we discussed and elaborated on the process of tool
construction.
The main purpose of any tool is to obtain data which is reliable and valid so
the researcher can read the prevalent situation accurately and arrive at some conclusions
to offer some suggestions. However, no tool is perfectly reliable or valid. So, it should be
accompanied by a statement of its reliability and validity. Here, in this chapter, the
estimation of reliability and validity of the inventory constructed are discussed along
with its norms in detail.
6.2.0 Reliability :
Reliability of a test pertains to reliable measurement which means that the
measurement is accurate and free from any sort of error. Reliability is one of the most
essential characteristic of a test. If a test gives same result on different occasions, it is
said to be reliable. So Reliability means consistency of the test result, internal
consistency and consistency of results over a period of time.
According to Anastasi and Ubrina (1982)1
“Reliability referes to the consistency of scores obtained by the
same persons when they are re-examined with the same test on
different occasions, or with different sets of equivalent items, or
under other variable examining conditions.”
Reliability is defined mathematically as the ratio of the variation of the true
score and the variation of the observed score. Or, equivalently, one minus the ratio of the
variation of the error score and the variation of the observed score.
r . is the symbol for the reliability of the observed score x, and x2,
T2 and E2 are the variances of the measured, true and error scores respectively. However,
there is no direct way to observe or calculate the true score, so a variety of methods are
used to estimate the reliability of a test.
84
