Another aspect of the experimental method is choosing the participants and the setting. The participants need to represent society as a whole and this can be achieved through randomization, which means allocating people at random. However, trying to create a truly random group of participants is often very hard because usually very similar people volunteer for psychological studies (like college students). Many experiments use a group (experimental group) and change something around them, like their environment. The setting can also be chosen between a laboratory setting and a field experiment, which are experiments conducted in the natural environment of the chosen participant. Field experiments tend to be less artificial but it is much harder to control variables accurately. Laboratory experiments are therefore used much more often in the experimental method.
A particular strength of the experiment is that it is the only one that investigates the ‘cause and effect’ of psychology. However, it is hard to accurately achieve this, since the experiment has to be controlled and confounding variables avoided. For example, in the subway investigation by Piliavin et al, the cause was the appearance of the ‘victim’ collapsing and the effect was the participant’s reaction towards helping the victim. The drunk victim received far less help than the cane victim and demonstrates a causal effect of the appearance towards the behavior
Another strength of this method is the ability to replicate a previous experiment. In theory, if the experiment was controlled and had no confounding variables you would be able to repeat it and find the same results. Even though this is extremely hard to do, it is easiest with the experimental. It is much harder to replicate a quasi-experiment for example because the “manipulation of the independent variable is often not in the control of the experimenter” (Eysenck 819). It also does not work in naturalistic experiment because they usually evolve around a naturally-occurring event (for example a natural disaster). So the experimental method proves to be the most suitable out of all other methods for replication.
A significant limitation of the experiment is that in order to control all variables psychologists often create and artificial environment (for example in laboratory experiments) which does not always truthfully reflect the real world situation. This is very useful in avoiding confounding variables, but the artificiality of the environment may affect the participant’s behavior. The participant will not act the way they normally do in their natural environment (for example in social situations). For example the subway Samaritan experiment would not have worked properly as a laboratory experiment. If the participants knew they were being observed the majority would help the victims, to prove they are good people. The effect of the participant knowing that they are being observed is extremely important to the validity of the results. Naturalistic observation however, makes sure that the participant is in their natural environment and is not aware of being observed and it can produce more valid results in that area.
Another limitation is that there are several ethical issues that concern the experimental method, which have to be avoided by the investigator. This, however, can make it difficult to perform the experiment correctly. There are certain rules to be followed, for example informed consent, right to withdraw, confidentiality of results, justification for lying, use of animals, and debriefing. Informed consent however would completely disrupt field experiment, like the subway Samaritan where the participants were not asked to participate and they weren’t given the right to withdraw. If they had been given it the participants would have known they were being observed, and the results would not have been valid. In laboratory experiments however, it is common that the participants are given consent, and it usually doesn’t impact the experiment any further since participants usually volunteered for the study. However even laboratory experiments, like the Milgram and the Stanford Prison experiments have been regarded ethically unacceptable (Eysenck 787). In the Milgram experiment the participants were lied to, thinking they were shocking a person up to 450 volts electricity, while it was actually just an actor pretending to feel pain. In the Stanford Prison experiment the participants were mentally, emotionally and physically harmed, even though Zimbardo (who led the experiment) had them sign a consent form and held debriefing sessions. Even though these experiments were debated unethical, they showed us significant insight into human behavior, which could not have been achieved with other methods or hypothesis. Today, psychologists have “become more aware of their social responsibilities towards the individual research participant” (Eysenck 787).
Altogether the experimental method relies on a tight control of the variables, and a valid manipulation of the independent variable to investigate the cause and effect, described in the hypothesis. It is difficult to avoid confounding variables that could disrupt the experiment completely and therefore it is also difficult to replicate it accurately. Experimenters also need to follow distinct rules to provide ethically acceptable experiments, which can make it difficult to investigate certain hypothesis. However the experiment is the only method that is closest to providing the most accurate results and is the most commonly among psychologists.
Works Cited
Eysenck, Michael W. “Psychology”. New York: Psychology Press Ltd., 2001.
"Revision:Pro and Anti Social Behaviour (A Level Psychology)." The Student Room. Acumen Professional Intelligence. 10 Oct 2008 <http://www.thestudentroom.co.uk/wiki/Revision:Pro_and_Anti_Social_Behaviour_(A_Level_Psychology)>.
Rupert, Dennis. "The Milgram Experiment." New Life Community Church. 10 Oct 2008 <http://www.new-life.net/milgram.htm>.
Piliavin, I.M., Rodin, J.A. & Piliavin, J. (1969) Good Samaritanism: An underground phenomenon? Journal of Personality and Social Psychology, 13, 289 -99)
