Psychological research helps us understand human thoughts and behaviors. Research methodology can be a deceptively difficult field to analyze. Research in psychology and the social sciences can be especially difficult to grasp because often the variables must be defined before they can be tested. Unlike in chemistry, where one chemical can be mixed with another and the effect analyzed, to analyze the effect of, say, stress on aggressive behavior, the variables “stress” and “aggression” must be defined in quantitative terms. There are some conventions in social research that make it easier to determine whether or not a psychological test is effective.
How to Know If a Psychological Test Is Effective?
- Make sure your test is valid. Validity refers to the degree to which a test measures what it is supposed to measure. A valid test of prejudice will measure how prejudiced a participant is without measuring any other aspect. A valid test will provide predictable and consistent results that have meaning. A test may have high face validity without having strong content validity. That is, at face value, a test may appear to measure what it is supposed to measure without actually measuring it. Validity is not determined by a single statistic, but it is built up after numerous trials and tests of accuracy.
- Ensure you have a reliable test. Reliability refers to the degree to which the test agrees with experts’ findings and similar tests’ results. A reliable test under the same conditions will come up with the same results every time. A test is not reliable if it violates previous knowledge. Another way to measure reliability is to compare the results of one test with those of another test designed to test the same relationships.
- Avoid extraneous variables. Extraneous variables are unintended influences on a test’s results. For example, fatigue can be an extraneous variable on an intelligence test if the test is conducted at midnight. Extraneous variables can completely change the outcome of a test and ruin a study. The best way to avoid the impact of extraneous variables is to have a large sample size, i.e., test a lot of people, and to use random sampling, i.e., grab people from a population at random; that way, the influence of extraneous variables will average out to a statistically insignificant number.