Following is the qualities of good psychological tests:
1. It is Reliable
A test is reliable only when the results remain constant whatever the environment or on different occasions.
It alsomeans consistency of the scores of the subject when tested again and again the results change, the test is inconsistent and unreliable. How to make a test reliable? There are three important methods:
(a) Test/Retest Method.
(b) Split-half Method.
(c) Parallel Forms.
2. It is Valid
An index of validity shows the degree to which test measures, what it purports to measure when compared with accepted criteria. The first essential quality of a valid test is that it is highly reliable.
If the reliability of a test is zero, it will not correlate with anything. A test that yields inconsistent results (low reliability) cannot correlate with a measure of another variable.
3. It is Objective
Objectivity means freedom from personal opinion or bias of the examiner. A good test is free from the linkages and personal whims of the scorer. Essay type examinations are not objective-personal opinion counts.
4. There is Ease of Administering and Scoring
Readymade keys are available for calculating result. Administration can be easily done. Directions are clear.
5. A Standardized Test in Less Time Counseling
We have the example of 3 hours essay type examination with us. It is just miserable to stand guard duty for three hours.
Class/age/percentile norms are available. This helps in quick comparison of results.
Some More Facts about Intelligence Tests
1. The correlation of intelligence tests scores with school marks is substantial (0.5 to 0.6 is average).
2. Previous school achievement gives correlation with later school achievement to be equal or higher than the correlation between intelligence and later school achievement.
3. Intelligence tests and achievement combined in a battery give still better prediction about future achievement.
4. Intelligence tests correlate higher with standardized measures
Of achievement than with school marks
5. The degree to which intelligence tests are related to academic success depends upon the subject matter.