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Dinesh Kumar, Lovely Professional University Unit 6 : Validity – Types , Methods and Usability

Unit 6 : Validity – Types , Methods and Usability Notes

CONTENTS

Objectives
Introduction
6.1 Validity

6.2 Types of Validity
6.3 Methods of Validity
6.4 Usability of Validity

6.5 Summary
6.6 Keywords
6.7 Review Questions

6.8 Further Readings

Objectives
The objectives of this unit can be summarised as below :
• To discuss about the validity
• To describe about the types of validity
• To explain the different methods of validity
• To describe the usability of validity

Introduction

The tests in the field of education are generally constructed to measure some specific qualities or
abilities (variables) of the students. If a test measures the qualities or abilities for which it was
constructed, then such a test is called valid, and this quality of the test is called validity. For example,
take an achievement test. If this test measures the knowledge, skill and sentiments for which it was
made, then it will be called a valid test and its this quality will be called validity.
It has been seen that no test comes fully true on the criterion of validity. A test neither has validity
fully, nor it is absent altogether. So now it is said that the more a test is able to measure the qualities
or abilities for which it is constructed, the more valid it is. Cronback has defined it in the following
words :
Validity is the extent to which a test measures what it purports to measure. —Cronback
That is the length of the test should be increased 6 times. Thus, it order to increase its validity from
.60 to .90, the number of questions will have to be increased from 50 to 300, that is, 250 questions
will have to be added to it. We will discuss about validity of test in this unit.

6.1 Validity

6.1.1 Meaning and Nature of Validity
Validity is an extremely essential attribute of a test. By validity is meant that characteristic of a test
under which it is understood that it measures that element or attribute for which it has been
constructed. The extent to which a test measures what it purports to measure is called its validity.

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