Scientific method in psychology

¶ … psychologists conduct research on a variety of topics that follow the basics of scientific methodology. They identify a specific problem, determine the appropriate methodology to study that problem, collect the required data, analyze and interpret that data and report their findings and conclusions. This approach has long been a part of the science of psychology.

The term "science" denotes both a certain type of activity and its results (Wolman 1960, p. 497). Frequently, delineation is made between the actual "research" conducted and the resulting "system," which are both described as scientific. Scientific research is aimed at the discovery of truth and a scientific system includes propositions, statements or sentences that represent this truth (Wolman 1960, p. 497). Whitehead (1911 p. 157) noted that common sense is "a bad master for the evaluation of knowledge." Science revolves around the terms "systematic" and "controlled." Scientists systematically build theoretical structures and exam them for any existing inconsistencies. Further, in scientific research, the scientist attempts to delete variables that are potential causes of the effects and not those that are hypothesized to be causes.

The concept of scientific thought stems from the end of the Middle Ages when Renaissance thinkers renewed their interest in learning. From the 15th to 17th centuries, scientists gained a strong appreciation for the importance of mathematical reasoning and experimental observation. Nicholas Copernicus described the mathematical harmony of the world (Franklin, Allison & Gorman 1996, p. 24). He reasoned that there was a mathematical simplicity to the heavens, suggesting that the planets and earth revolved around the sun. Johannes Kepler's desire for geometrical perfection drove his scientific ideas about the planets' orbit. Galileo clearly recognized the value of experimentation (Franklin, Allison & Gorman 1996, p. 24). The concept that the method of inquiry was the key to all knowledge was clarified by Francis Bacon, which formulated the logic of inductive reasoning to give scientists an approach to follow. The first stage of Bacon's inductive investigation was methodical observation, which requires the investigator to create a diverse list of all positive instances of the phenomena being studied. Next, the researcher finds situations similar to those on the first list where the phenomenon is absent. Finally, the scientist generates a list of degrees where the instances are ordered according to the quantity and intensity of the phenomena. In the second stage of scientific investigation, according to Bacon, one inductively generalizes from the data by locating substantive correlations. This is possible by finding a cluster of properties such that it "is always present or absent with given nature and always increases and decreases with it" (Bacon 1939, p.110).

Bacon was so positive that this set of properties meeting such established conditions caused the phenomena that he declared, "the discovery of all causes and sciences would be but the work of a few years" (Bacon 1939, p. 75). Although Bacon's promise proved to be impossible, his method did indeed become the model for the sciences. As noted by Whitehead (1911 p. 157), the scientist, when trying to explain the relationships among observed phenomena, systematically omits metaphysical explanations, or those that cannot be tested.

Thomas Hobbes furthered the ideas of Bacon by developing one of the first mechanistic accounts of human cognitive processes (Verberg 1969). He also looked for empirical laws to explain the origins of society and government based on the fact that humans have a natural drive for survival. It was Rene Descartes, however, who radically furthered the idea of scientific study by rejecting any idea that could not be proven with certainty (Franklin, Allison & Gorman 1996, pp. 25-26.). He noted, "We reject all such merely probable knowledge and make it a rule to trust only what is completely known and incapable of being doubted" (Descartes 1970, p. 3).

In his belief of rationalism, Descartes argued that everything is explainable through one overarching system of reasoning that is deductive in nature. This idea was in contrast to Bacon and Hobbes, who believed experiences were the basis of all learning. Descartes modeled his approach on mathematics, since he reasoned that the mind could be trained to produce clear and consistent truths as one can deduce theorems from axioms through proofs.

Because Descartes' methodological rules were too strict for broad scientific applications, John Locke instead argued that the mind was a clean slate upon which experiences left their mark (Franklin, Allison & Gorman 1996, p. 26). This theory of knowledge formed the foundation of scientific psychology, since he attempted to analyze the mechanisms of the mind. For instance, Locke hypothesized that all complex, abstract ideas were constructed from simple, concrete ideas produced through one's experience.

Isaac Newton combined all these earlier philosophies into a single working theory. He realized the importance of both the deductive, mathematical approach supported by scientists such as Descartes as well as the inductive experimental methodology backed by Bacon. Newton integrated his own and other scientists' observations concerning the effect of gravity into a universal explanation in the form of a mathematical relationship indicating (Mason & Bramble 1978, p. 2). Newton's successes in the physical sciences encouraged those in the human sciences to follow suit.

The purpose of scientific research is to explain the relationship among phenomena that occurred naturally and then use these to predict future events (Mason & Bramble 1978, p. 3). Research is the means by which scientists find the knowledge to formulate their theories. The scientific method provides for the systematic investigation of a hypothesis. When data are consistent with a hypothesis, that hypothesis is supported and further knowledge gained (Schweigert 1994, p. 6).

The scientific method, whether it is used for psychology or engineering, is normally described using five steps. These steps are not necessarily always done in the same order. The first step is identifying a specific problem. This is done by sensing or recognizing that some issue exists by becoming familiar with topic being covered. For instance, something may have occurred that has not been properly explained or the manner to accomplish some goal may not be evident (Mason & Bramble 1978, p. 27). At this point, it is also necessary to determine what has already been researched on the topic.

The next step is to design the study so that the results can either support or refute the hypothesis. This is the stage when it is necessary to decide exactly how the observations will be made. This is completed by defining the terms and designing the investigation. There are a variety of qualitative and quantitative research designs that can be used, each with their advantages and disadvantages. The decision is usually made by weighing the pros and cons of possible approaches and finding the one with the best balance (Schweigert 1994, pp. 16-17). At this time, one must also decide the subjects in the study, number of subjects needed, means for testing, time period studied and the researcher/subject interaction.

Once the research design is completed, the psychologist makes the observations and collects the data as prescribed. Flexibility is required at this point, since the researchers may come up with surprising data and have to redesign their approach. The major task of the observer is to record information with as limited inference and bias as possible. Objectivity and accuracy need to be maximized (Franklin, Allison & Gorman 1996, p. 78).

The data is then analyzed. Various methods of calculating the data are used. For example, the unweighted additive method involves calculating the arithmetic mean or sum of the component variables that make up th behavior composite. This method is the easies to perform and one that is the most used by behavior analysts.

The next step is interpreting the data and folding that into a larger body of knowledge about the phenomena (Mason & Bramble 1978, p. 27). This may involve consideration of pervious knowledge in terms of new information or further experimentation.