Tests of Sound measurement implies the tests of validity, reliability and practicality.
Tests of validity: It is the most important criterion of Tests of sound measurement and means the degree to which an instrument measures what it is suppose to measure. It can also be taken as utility. There are three types of validity to be considered in this connection:
Content validity-this provides ample coverage of the current study. If the representative sample of universe is contained in the instrument, the content validity is considered to be good.
Criteria-related validity– this implies the ability to predict result or estimate the existence of present situation. The concerned criteria should possess the following characteristics:
- Relevance
- Freedom from bias
- Reliability
- Availability
Constructability: is termed as the most complex and abstract. If the measure confirms to the degree that it relates to predicted correlations with the other theoretical propositions. In order to determine construct validity the researcher associates a set of propositions with the results that are received from making use of the measurement instrument. It could be concluded that there is some construct validity if the measurement on the devised scale correlates with the other propositions.