The whole variety of possible psychological tests may be divided into several groups on based on the particular questions on mind's work being studied as well as the inputs/outputs of a black box being taken into consideration. As for any other classification tasks, there are multiple possible divisions, but it's my firm believe that the most appropriate way, which considers the intrinsic peculiarities of the human mind as the main subject for both the testing problem and this essay, is the division on two general groups: the tests, which deal with the human personality and those, which study the cognitive functions. The first claim that my personal mind sets up at this point is to define the personality and cognitive functions in such a way, that all the possible psychological tests would clearly fall into either of these categories. Unfortunately this is a rather difficult task to carry out in a formal way and it may take a separate paper to do properly. Fortunately we may do it with the use of example as well.
- Imagine that we have a subject and we want to measure how fast s/he reacts on some audio stimulus, say the gunshot. The instruction asks to push the button immediately after the gunshot is heard. In this case the input is the audio signal, which is provided through hearing and the output is the time, which passes before the subject presses the button after the gun actually shot. Having a certain amount of results, we may count the simple average, dispersion and other figures on the subjects' audio-motor reactions.
- Imagine that we need to estimate the person's hostility and aggression level. To perform this, we ask a person to answer a number of, say, 75 yes/no questions. Then we count the number of questions that very hostile people are known to answer the same way as our subject does. Then we compare this number with the scale, determined by the comparison with the results of people of different levels of aggression (as defined by the psychological interview or any alternative method).
It is easy to notice, that there are certain principal differences between mental tasks, which the tests from the examples above are intended to assess. The first one performs a simple reaction time measurement, while the second one deals with personal attitudes to other people, i.e. it is connected to "emotions" or "finer feelings". The first one is the example of cognitive functions test, while the second one rather belongs to the type of personality tests. There are also theoretical and implementation differences between these types of tests, but since the topic of this essay is constrained with the cognitive functions assessment, we are not going to dwell on the personality issues any further.
Ivan Tugoy, 2003