Five main characteristics of a good psychological test are as follows: 1. Objectivity 2. Reliability 3. Validity 4. Norms 5. Practicability!
The test should be free from subjective—judgement regarding the ability, skill, knowledge, trait or potentiality to be measured and evaluated.
This refers to the extent to which they obtained results are consistent or reliable.
When the test is administered on the same sample for more than once with a reasonable gap of time, a reliable test will yield same scores. It means the test is trustworthy. There are many methods of testing reliability of a test.
It refers to extent to which the test measures what it intends to measure. For example, when an intelligent test is developed to assess the level of intelligence, it should assess the intelligence of the person, not other factors.
Validity explains us whether the test fulfils the objective of its development. There are many methods to assess validity of a test.
Norms refer to the average performance of a representative sample on a given test. It gives a picture of average standard of a particular sample in a particular aspect. Norms are the standard scores, developed by the person who develops test. The future users of the test can compare their scores with norms to know the level of their sample.
The test must be practicable in- time required for completion, the length, number of items or questions, scoring, etc. The test should not be too lengthy and difficult to answer as well as scoring.