A psychometric instrument is said to be valid if it measures what it claims to measure. This questionnaire is valid as it measures the dynamics of Jung’s psychological types. The dominant attitude and function as well as the auxiliary functions are predicted and represented in each profile, and the factor structure supports the construct validity of the questionnaire.
Feedback confirms that the instrument has high face validity. It is accepted readily and respondents volunteer to complete on the internet without any other influences. The items are sensitive and construct free and the fact respondents cooperate of their own free will suggests that it provides no threat.