The Advantages and Disadvantages of Experiments in Psychology

29 Sep

Psychology uses scientific methods to support hypothesis, using these methods correctly ensures that the results are reliable, valid and objective. If a hypothesis is tested, and the result is supported, then it’s a valid theory as opposed to an opinion.

An experiment is when an independent variable is manipulated to measure the effects of the dependent variable. In an experiment the situation is controlled, and there are as little confounding variables as possible. This way we can observe the cause and effect relationship of both variables. If the experiment is repeated enough the result is considered reliable, as long as the results are similar. Without methods of testing theories then there is no way of knowing what is a tested theory, and what is opinion.

The main advantage of experiments is that it’s very likely that it’s the independent variable that is manipulating the dependent variable, not a confounding variable. Anything that manipulates the dependent variable, that isn’t the independent variable is considered a confounding variable. In an experiment, the cause and effect relationship is clear as there are as little variables manipulating the dependent variable as possible.

Some may say experiments are too controlled. The results from that experiment may only apply to that one situation; therefore it would be a mistake to apply the results to all situations. The way one group of people in a controlled environment behave is different to the way another group behave in another environment. The participant in an experiment may alter their behaviour, they might change their behaviour or answers to the ones the researcher might find preferable just because they’re in an experiment. This problem could be resolved if the person doing the experiment doesn’t let on which answer is preferable. A double blind study would also be a way around this problem, this would mean that the researcher would have no contact with the participants, and would have someone else who has no idea of the expected result of the experiment conduct it, so the data collected would not be biased.

There are also field experiments, this would be the ideal solution if being in an experiment modifies behaviour, or to have the results reflect everyday behaviour. A field experiment would be conducted in a real world surrounding, so the participants would feel more at ease and their behaviour in real life situation would be shown. The disadvantage to field experiments is that there are more confounding variables and less control of the situation, so we might not be sure if it’s really the independent variable effecting the dependent variable, or if there’s a confounding variable.

It could be argued that simplifying behaviour into two variables might be over simplifying a complex thing, and the results might not be valid. For example if GCSE results were used as a measure of intelligence this would be over simplifying, as effort in school and home life might have an effect on the grade, not just intelligence. If this isn’t a valid measure, then it would effect the validity of the result. However we can overcome this by cross referencing the GCSE results to another measure of intelligence, such as an IQ test.

Experiments are replicable. If the researcher shows the methods clearly when publishing the research, other psychologists are able to do the experiment for themselves. This is an advantage as it’s a way of knowing if the results gained were because of chance. If other researcher get the same results then they are reliable, and scientific data is gained to support the theory.


Posted by on September 29, 2011 in Uncategorized


3 responses to “The Advantages and Disadvantages of Experiments in Psychology

  1. psuea7

    October 1, 2011 at 2:01 pm

    Experiments are important in psychology but each method has its flaws. lab experiments are often said to lack ecological validity as they take place in an artificial enviroment and do not give a fair representation of how someone would behave in a real life situation. Also in many lab studies the participant is awear they are taking part in a study, even if they are unawear of what the aim of the study is. because of this there is the chance that they may behave differently to how they normaly would to apear more politicaly correct, although this is not always consious. this is known as demand charictoristics and can geatly impact the results of an experiment. In field studies as said above there are more confounding variables to consider and less controle over the enviroment. This means that it is difficult to be certain that it is the independent variable impacting the dependent and not the result of one or more confoundind variables. Athought there are less confounding variables in lab experiments they still can impact results. this could be something as simple as the participants mood on the day of the study.

    Some psychologist belive that experiments do not gain a full insite into the participant, because of this some psychologist conduct case studies instead of experiments. As case studies focus on a singular individual their results cannot be generalised and reliability cannot be assesed as case studies cannot be repeated. The way they are interpreted is also subjective and often depends on the oppinion of the observer.

    Because of this lab studies, although critisised for lacking compleate ecological validity are probably the best way of invesigating a psychological theory.

  2. kp1203

    October 3, 2011 at 11:12 am

    Experiments are undoubtedly the most controlled way of gaining research data, they allow the independent variable to be isolated to prevent extraneous variables affecting data, thus establishing a cause and effect relationship between the variables. However the lab experiments often lack ecological validity for example Dement and Kleitman made their participants sleep in a lab whilst undertaking EEG scans, the environment is unlike their usual sleep condition however it is vital to keep conditions controlled. Lab experiments, being low in ecological validity are often hard to generalise from as the environmental conditions aren’t natural, however they are often used as they are the only appropriate technique.
    Field experiments on the other hand, are useful in demonstrating behaviour in real life situations and therefore are more generalisable to real life situations such as Piliavin’s study of Samaritan action on a subway train. Despite being useful as being high in ecological validity, field studies unfortunately have their problems such as lacking in control. If a study is in a real life situation or public place the researcher has little or no control over what happens and extraneous variables are a serious problem as they affect the reliability of data.

    It is extremely hard to gain the balance between controls and ecological validity; the two main aspects gained from/lacking in lab and field experiments.

  3. djaic

    October 4, 2011 at 11:37 am

    I agree that all ranges of experiments are useful for research in psychology. For instance Milgrams laboratory experiment is a great example of how laboratory experiments are necessary and helpful. Also, in some research situations, field experiments would be the most appropriate type of experiment, for example when researching discrimination or clinical trials for pharmaceuticals.

    However, all of these methods have there flaws, may it be ecological validity or low contro over extraneous variables. Therefore however statistically significant the results are, the experiment will always have its disadvantages. As a result, I think that where possible, observation (naturalistic/controlled) is a sound means of research, Mary Ainsworth’s findings from her Strange Situations observations are of high validity. However, in many situations an observation is not possible.


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