Psychological testing is the execution of psychological tests. It is done only by expert psychological testers. In this, you have to record the response of the psychic patient within a time frame. The basis of psychological testing is “Psychometrics”. Psychometrics is the psychological measures on which the test is constructed.  Psychological testing involves the careful observation of the focused sample of individuals and their responses. Psychological tests are constructed to observe the unobservable, which is also called as “Latent Variables”. The testing can include a lot of tasks and problems that the patient has to solve in order to complete the psychological testing.  To measure the results the observer may include the questionnaires and interviews. They are also designed to evaluate the unobservable facts about the respondent. However, these questionnaires and interviews are not psychoeducational. Attitude tests and symptoms are involved in scales.  A valid psychological test is the one that is reliable and valid as well.
 
https://en.wikipedia.org/wiki/Psychological_testing