What is validity? Explain the forms of validity.
An important characteristic of a good research tool is validity. Validity refers the extent to which an instrument measures what it is supposed to measure. It shows the degree to which a test measures what it purports to measure. The test should answer the following question:
Is the test measuring what it is supposed to measure?
So validity is " the extent to which the test actually accomplishes what it aims to accomplish."
The first essential quality of a valid test is that it should be highly reliable. A test which is unreliable, cannot be valid.
The following are the forms of validity:
a) Content validity
b) Predictive validity
c) Concurrent validity
d) Construct validity.
CONTENT VALIDITY: The content validity refers to the degree to which a test samples the content area which is to be measured. Educators are more concerned with content validity. Content validity is essentially based on the judgement of experts. The test maker may contact a number of experts in the relevant field. They will be asked to examine the test items systematically and indicate whether they represent the content area. Thus an expert judgement is taken to verify whether the test items are related to the objectives or not. This type of validity is also called face ...