Psychologists who want to determine how a human or animal responds in his or her natural environment may use observation. Researchers may observe students in the classroom or animals in their natural habitat. With this research method, the researcher generally observes an individual or animal without his or her consent to prevent their awareness from causing results that would not naturally occur. Observational studies are generally considered the most natural method of research because the psychological researcher has little control over factors that may impact results.
Correlational studies examine the relationship between two variables. Studies which use this psychological research method aim to find a positive or negative correlation between the two variables which are being measured. For example, researchers may try to find a correlation between smoking cigarettes and obesity or diet and lung cancer. Although correlational research studies allow psychologists to determine the relationship between two variables, it is not possible to determine cause and effect based on their results.
Experimental research studies, also known as true experiments, measure at least one factor. The psychological researcher controls one or more variables throughout the study. Participants are randomly assigned into two groups, the experimentation group or the control group. The experimentation group receives treatment, while the control group is used to compare the results found. Since the researcher is able to control variables during this type of study, experimental research is generally regarded as one of the most effective psychological research methods.
Psychologists sometimes conduct surveys to get opinions, beliefs or find a correlation between variables using a random sample of the population. Surveys are generally given to a random group of the population in question, such as liberal college students or mothers with 3-year-olds. While surveys are a common method of psychological research, some doubt how honest survey takers are. Individuals may feel uncomfortable answering questions about controversial or embarrassing issues, such as abortion, the death penalty and sexual intercourse.