Personality Measurement: Assessing the Dimensions of Personality
To measure, say, a person's height, one uses a ruler. Scientists call height a physical dimension. Length, width, and weight are also physical dimensions. Such dimensions are often easy to measure, if we have the proper instruments.
What are the dimensions of personality? How can we measure them? Generally, we are not dealing with physical measurements, nor with physical objects. Also, personality is complex. It is not simply black or white in the sense of simple typology. Rather, there are many in-between shades of gray. For example, when we say that Sally is "warm", or "friendly", we mean that she behaves warmly more often and in a greater variety of situations than many other people. Psychologists would call social warmth a dimension of personality.
Psychologists can measure warmth and other personality dimensions, such as intelligence, honestly, happiness, and so on. They have developed tests, scales, and experimental situations to compare one person with another.
The simplest procedure is to observe what people say and do in real-life situations. All of us do this when we are with other people. We watch and compare their habits, speech, and dress, thus learning much about them.
Then why are we not all experts in personality? There are a number of reasons. First, we cannot observe everybody in all situations. Second, we cannot remember every situation and what happened in it. And, third, we have our own personal opinions about people and events. These opinions make it difficult for us to be scientifically accurate. In other words, our own personalities influence our perceptions of other people.
To make personality observation and measurement an exact science, psychologists collect information under controlled conditions. That is, they test and record people's behavior under the same set of conditions. This is the only way they can compare people's personalities accurately.
Large-scale personality measurements must use convenient methods to accommodate the number of people that they encompass. Here, written tests are important. One example of a written test is the personality inventory. The subject answers questions about his or her life, attitudes, habits, and problems. The questions often call for short and clear-cut answers. The subject may only have to answer "true" or "false". Or he may have to choose one of several answers already given to each question.
Other personality tests are less structured. A subject may be asked about his reactions to drawn patterns or pictures. He may even be requested to draw pictures and write stories. The subject may answer by speaking rather than writing. These kinds of tests are called projective tests: the subject throws, or projects, his/her feelings and attitudes onto the persons and objects he/she sees or discusses.
There are other kinds of psychological examinations and measurements, conducted by interview, in mental clinics, and in make-believe situations that the subjects, however, think are real. There are no right or wrong answers. Only the truth is important. But many people knowingly lie in these tests, because they are afraid to reveal themselves. Or they try to give answers they think the examiners will like, especially if they want to get a job or to leave a prison or a clinic.
If we could measure a person in each dimension of personality, we would get a pattern, or cluster, of scores that represents him or her alone. However, no single test measures all the possible dimensions. Rather, different tests measure different dimensions, depending on the purpose of the test.
