An especially troublesome type of response set is social desirability . This is the tendency to respond to the items in a way that is socially acceptable or desirable, regardless of the true or real attitudes of the individual. Faking is usually dependent on the purpose of the test and the consequences of the results. A test is an instrument that requires subjects to complete a cognitive task by responding to a standard set of questions. The answers to the questions are summarized to obtain a numerical value that represents a cognitive characteristic of the subjects.
All tests measure performance at the time the test is given.
Test differ in how the results are used, in their development, and in the types of validity and reliability that are established. Here the score is interpreted by comparison to a standard or criterion rather than to the score of others. Typically the norm or reference group has the same characteristics, such as age and grade level, as the subjects in the study. Standard Scores transformed raw scores that have a distribution in the same shape as the raw score distribution but with different mean and standard deviation. The most basic standard score is called a linear z score.