Drawing on evidence from studies, what are the advantages and disadvantages of these methods? There are three main methods of investigation which psychologists use. This essay will describe these methods: experiments; surveys; and observations; together with a summary of the advantages and disadvantages of each. The first means of investigation is the experimental approach. An experiment is an empirical study where the researcher makes things happen by manipulating a factor, referred as the independent variable, and records the effect on another variable, known as the dependent variable.
The experimenter deliberately intervenes in order to see what impact their intervention has on the outcome. In psychology, the main form of experiment tends to be controlled experiments, where there is a control group, which acts as a baseline in comparison with the experimental group. An important feature of a controlled experiment is the random allocation of participants to the two groups, so that there is no systematic bias in forming the groups. This is called randomisation.
A key advantage of the experimental method is that it is the only technique by which cause and effect can be determined. In other words it can show whether one variable is causing a specific impact on another variable. Another advantage is the fact that the findings tend to be quite easy to interpret is of benefit to the experimenter. The experiments are usually carried out in the laboratory which is also convenient for the experimenter. There are, however, some important disadvantages associated with this method. The experiments can be time consuming.
The fact that the experiments are often undertaken in the laboratory, which is not the participants’ natural environment, means that their behaviour may contrived, rather than as they would react or behave in true life. Similarly, the experiments seem very artificial, as only one variable may be manipulated at a time, so they do not resemble real life situations. A very important disadvantage is that, because the participants know that they are being watched, they may consciously or subconsciously change their behaviour or react differently from how they would normally if they were not under scrutiny.
In some circumstances, participants may even decide to try to outwit the experimenter by giving the opposite response to their natural one, although the majority of participants tend to co-operate in order to be helpful. In a study performed by Milgram (1963, 1974), it is thought that Milgram himself inadvertently influenced participants, thereby rendering his results unreliable. Inaccurate results can also occur due to experimenter bias, so any researcher has to be very careful to avoid unintentionally altering the results, Barber (1976).
] The second main investigation method is by carrying out surveys, interviews and other non-experimental methods. This means that the researcher is gathering evidence without attempting to intervene in terms of affecting the outcome. In some ways this can be seen as the simplest form of investigation. It is used when the researcher is interested in what people are thinking/feeling or doing, rather than in what the cause and effect links are.
This method involves asking people questions, be it in the form of an interview, telephone or on-line survey or self-completed questionnaire. The questions may be presented in a structured format where there is a standard list of questions asked of all participants set out in a standard order. The structured approach can be used in one to one interviews. It is also possible to conduct a semi-structured interview is based upon a standard list of questions which the interviewer may expand upon in order to clarify and develop certain responses.
An unstructured interview, is one in which the questions asked about the topic of interest and the shape and direction of the interview varies with each interviewee. Such interviews can produce a rich source of material but, unless been handled by very experienced researchers, they can be difficult to analyse and draw conclusions from. Sometimes inexperienced researchers conduct unstructured interviews without foreseeing the problems that they will face in making effective use of the information obtained.