Psychological tests are common tools used by schools, hospitals, companies, and other institutions in order to assess the personality of a particular person. Such tests apprise individuals of their personalities, including their behaviors and what they are capable of doing. The history of personality assessment is very long. It might be possible that assessing personality had been of existence since the time a man tried to assess the personality of a stranger for the first time. However, formally assessing personality first became popular in the beginning and the end of World War II.
The first tests were paper-and-pencil group tests which consisted of multiple choice and true-or-false questions administered to a large group (Kaplan, et al, 2005). What is a Test? According to the Merriam-Webster dictionary, a test is a critical evaluation or observation. It is also a procedure wherein a statement is being submitted and subjected for acceptance or rejection. Basically, it is a procedure. As related to psychology, it is used to measure skill, intelligence, capacities, or aptitudes of an individual or a group (Test, n. d. ). Categories of Psychological Testing
Basically, there are two categories of psychological tests. According to a book entitled, “Psychological Testing: A practical Introduction”, the two categories are Normal Personality Traits, and Clinical Instruments (Hogan, 2007). The similarities between these two categories involve the nature of the test items and the response formats. Both tests use simple statements as test items, as well as response items. Basically, these items can easily be answered by a simple response such as yes or no. The second similarity is that these categories are subcategorized into comprehensive instruments and specific domain instruments.
The aim of the comprehensive clinical instruments is to survey all potential areas of difficulty. In order to do so, these tests produce numerous scores. The specific domain instruments however, focus in only one particular area such as depression, anxiety, or eating disorders. These tests produce only one type of score or a few number of closely related scores. Both normal personality traits and clinical instruments also involve similar strategies for development such as criterion-keying and both have the same stand on faking and responses.
Aside from similarities, the two categories of psychological tests also have a number of differences. Firstly, normal personality traits focus on the normal range of personality while clinical instruments focus on the psychopathological aspects or some psychological difficulty. Most of the time, clinical instruments are administered individually, while normal personality traits are administered in a group setting. Clinical instruments are commonly used for diagnosis, treatment, and follow-up evaluation. Normal personality traits such as the NEO PI-R do not have that kind of characteristic (Hogan, 2007).
Reliability and Validity Reliability of a psychological test means that the results should be consistent. If a person, for example, takes a test, the result of that specific test should be consistent for a considerable period of time. If in any way the result of a test is not the same with an already proven reliable test for a particular person, then that test is not reliable. Thus, reliability is proven with the use of a coefficient correlation between the test scores of the first testing and the second testing.
The correlation coefficient (r) is a numerical summary of the relationship indicated in a bivariate distribution. This is computed by defining first the formula for r and computing its raw score (Hogan, 2007). The coefficient for a perfect reliability is +1. 0 while a coefficient of 0. 0 means no reliability. Reliability can also be determined by comparing two psychological measures (McCurley, et al. , 2005). The difference of reliability from validity is that validity is determined whether a particular test is appropriate for the condition to be measured.
It is important that an intelligence test should measure and intelligence and a personality test measure personality. The American Psychological Association issued a book entitled, “Educational and Psychological Tests and Manuals” in order to help practitioners in the field of testing determine the validity of a certain test (McCurley, et al. , 2005). It should be noted that it would be inappropriate to refer to the validity of a test in itself. Rather, what should be referred to be the interpretation of the scores, whether it fits the particular purpose.
A test may be suitable for a particular condition, but not to another. The question should be asked is if the interpretation of scores of a test fully addressed the level of the condition. Also, validity is not a matter of degree, as according to Hogan. It is necessary that what should be known is the extent of the validity for a particular condition, since some tests may have no validity at all (Hogan, 2007). Reliability and validity have their own significance in psychological testing. Reliability makes sure that tests are consistent and can be used universally to a large number of population.
It also makes comparing test results easier since these are standardized and their relationships are already proven appropriate. A test may have reliability without having validity. However, both are essential in determining accurately every individual’s psychological condition. Validity requires that the test is truly measures the entity it intends to measure. It is difficult to determine validity (McCurley, et al. , 2005). However, it is important that each test accurately measures what it intends to measure. Validity and reliability are interdependent in establishhing a trully effective psychological test.