Role of the scientific method in psychological research

Psychology - Scientific Method

THE ROLE of the SCIENTIFIC METHOD in PSYCHOLOGY RESEARCH

The Experimental Method in Psychology: In general principle, the scientific method is applicable to all areas of intellectual inquiry and experimentation. It refers to the process of formulating a hypothesis capable of being tested empirically. To qualify as a bona fide scientific hypothesis, a concept must be capable of being definitively disproved by an experimental design that is repeatable. Strictly speaking, it is impossible ever to prove that a hypothesis is true, because the full range of variables that may contribute to the experimental results may include those beyond the ability of the researchers to anticipate or recognize.

Therefore, no matter how many times a particular experiment yields consistent results, their combined data merely suggest relative degrees of correlation. Nevertheless, when a sufficient volume of consistent results is produced by a series of validly designed experiments, the degree of correlation between the variables under examination is sufficiently high that they are treated as affirmative proof of the hypothesis under consideration. For practical purposes, we consider repeated consistent experimental results as conclusive evidence, despite understanding that, in principle, nothing is ever capable of absolute affirmative truth (Gerrig & Zimbardo 2005).

In the field of psychology and psychological experimentation, researchers propose given hypothesis suggesting a relationship between variables that is capable of being tested by controlled experiment. An experiment is designed that examines the specific relationship between two variables. The range of variables is virtually limitless, but generally, the experimenter purposely limits them to those suspected of a correlative or dependent relationship without necessarily discounting other conceivable independent contributing factors (Carlson 2006).

For example, an experimenter may wish to examine the role of testosterone on male aggression leading to domestic violence within marital relationships. One experimental proposal may include measuring the testosterone levels of males arrested for domestic violence with those of men with no criminal history. A high degree of correlation between higher testosterone levels in domestic violence perpetrators in comparison to non-violators suggests that the initial hypothesis as to the relationship between the two variables is valid (Gerrig & Zimbardo 2005).

The value of any results of experimentation are only as valid as the experimental design. For example, in the above experiment, higher testosterone levels among domestic violence perpetrators would seem to substantiate the original hypothesis, but additional areas of inquiry are necessary to produce any level of reliability on those results. It may be that all criminals, rather than domestic violence perpetrators in particular, have higher testosterone levels than non-criminals because high testosterone is cause of criminal deviance of all types.

Therefore, a companion series of experiments is necessary to validate the usefulness of the first study, such as where the experimenter follows the initial line of inquiry with a similar comparison of testosterone levels between criminals and non- criminals, as well as between domestic violence perpetrators and non-violent criminals, and finally, between domestic violence perpetrators and violent criminals who do not have a history of domestic violence.

The Descriptive Method: Because psychology is an observational science, it necessarily relies on the experimenter to observe, catalogue, quantify, and interpret variables suspected of a causative relationship. While observation is, therefore, essential to the study of psychology, it also presents a potential weakness in the results observed (Carlson 2006). For example, in the above experiment, the experimenter could, through a series of well designed experiments, determine that: (1) domestic violence perpetrators have, on average, a higher testosterone level than non-perpetrators; (2) other criminals do not, on average, have a higher testosterone level than non-criminals; and (3) none of the domestic violence perpetrators have a lower testosterone level than either non-perpetrators or non- criminals. Those results would seem to validate the initial hypothesis, that high testosterone levels are a causal factor in male perpetrators of domestic violence. However, the preceding series of experiments establishes only that there is a correlation between high testosterone levels and domestic violence; it does not necessarily justify any conclusion that the former causes the latter. In fact, it may be the exact reverse: perpetrating domestic violence may be the cause of high testosterone levels rather than the reverse. Actually, researchers have determined that aggression and testosterone are sometimes related in precisely that fashion: aggression does sometimes raise testosterone levels temporarily (Gerrig & Zimbardo 2005).