Technically, a psychological test is a standardised and objective instrument. A primary characteristic is objectivity. This means that if two or more researchers administer the test on the same group, they would come up with more or less the same values for each person. To achieve this, items should be worded clearly, instructions specified in advance, and procedures for administration and scoring described.

For a test to be usable, it must also have validity. This refers to the question: “Does the test measure what it claims to measure?” For instance, a mathematics test should measure mathematical achievement, not language proficiency. The characteristic must be defined clearly, and all items must relate to it.

The construction of a test is a systematic process that involves estimating reliability. Along with validity and norms, reliability is a key component analyzed during the test construction process.

Finally, a test becomes standardised when norms are developed. Norms refer to the normal or average performance of the group. The test is administered to a large number of students to set performance standards based on age, sex, and place of residence. This helps compare an individual's performance with others and interpret scores.