Research Methods in Psychology: Gathering Data

The Scientific Method: Do the Facts Support Your Educated Guess?

The method of psychology used to investigate the behavior of human beings was rationalism. This is the point of view that great discoveries can be made just by doing a lot of hard thinking.

At an informal level, rationalism is sometimes called “armchair philosophizing.” Philosopher John Locke (1632–1704) decided that there are no inborn ideas. Immanuel Kant (1724–1804) concluded that the human mind does have some a priori information, meaning that there are inborn ideas of a certain kind. So rationalism alone is an unsatisfactory method for psychology if it claims to be a science.

Contemporary psychology combines rationalism with empiricism. Empiricism is the point of view that knowledge is acquired by using the senses—by seeing, hearing, touching, and so forth. Empiricism represents what William James called a tough-minded attitude.

Naturalistic Observation: Looking at Behavior without Interference

When people or animals know they are being observed, they may not behave in the same way as when they’re not being observed. Sometimes it is necessary for the researcher to allow for a period of adaptation to his or her presence.

The Clinical Method: Studying Troubled People

The clinical method is a research technique associated primarily with the treatment of individuals with mental or behavioral disorders. It arose within the associated frameworks of psychiatry and clinical psychology.

The Case Study Method: One Subject at a Time

The case study method involves the study of one individual over a span of time. It is similar to the clinical method. The difference between the two methods is that the subject in the case study method is not necessarily troubled.

The Survey Method: Large Samples from Larger Populations

A survey attempts to take a large, general look at an aspect of behavior.

The difficulty associated with biased sampling from a population of interest is a general problem, one that is not limited to survey.

The Testing Method: Mental Measurements

The testing method explores human behavior by using psychological tests of attributes such as intelligence, personality, and creativity. These tests are often of the paper-and-pencil variety, and the subject completes the test following a set of instructions.

Two problems associated with psychological testing are validity and reliability. A valid test measures what it is supposed to measure. A reliable test gives stable, repeatable results.

The Correlational Method: When X Is Associated with Y

The word correlation refers to the relationship between two variables. These are usually designated as X and Y on a graph. If scores on one variable can be used to predict scores on the second variable, the variables are said to covary. Correlation coefficients can range from −1.00 to +1.00.

The Experimental Method: A Tool with Great Power

The experimental method is a research tool characterized by a control over variables, the identification of a cause (or causes), and a well-defined measure of behavior. These aspects of the experimental method give it great power.

Four key concepts will help you understand the experimental method:(1) the control group, (2) the experimental group, (3) the independent variable, and (4) the dependent variable.

1. The control group receives no treatment; it is dealt with in a more or less conventional manner. It provides a standard of comparison, a set of observations that can be contrasted with the behavior of the experimental group.
2. The experimental group receives a novel treatment, a condition (or set of conditions) that is presumed to affect behavior. It is the target group, the one that will perhaps provide original or particularly interesting data.
3. The independent variable is one that is assigned to the subjects by the experimenter. There will be at least two values, or measures, of this variable. It is the variable that is thought of as a cause of behavior.
4. The dependent variable is a measure of the behavior of the subjects. In most experiments, this variable can be expressed as a set of scores. The dependent variable is associated with the effect of a cause. Scores make it possible to compute statistical measures and make evaluations based on the data.