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RESEARCHING THE REAL WORLD |
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The results indicated that exposure to beauty commercials (the treatment) had a marked effect on attitudes towards the two of the four roles. However, it is a small sample, there is no way of knowing whether the effect would be long-term nor what the prior disposition of the subjects were towards beauty. 9.1.3.3 The retest control group design 9.1.4 Control For example, an experiment to see how exposure to propaganda affected support for the Gulf War would need to take account of the gender of the respondent. Opinion polls suggested that at the outbreak of the war, a much larger proportion of men than women supported the war. Gender is thus a control variable in this case. It is often difficult to identify all the relevant control variables. Once the control variables have been identified some way of controlling for them has to be devised. One way of doing this is, in effect, to exclude control variables. In the previous example, one way of controlling for gender differences is to have all the experimental subjects the same gender. This is known as a homogeneous group. If the study group is all male then there may be a need to test the outcomes with an all female group to see whether the experimental results obtained are repeated. In practice, however, it is difficult to identify all the important control variables and to be able to assemble such homogeneous experimental groups. 9.1.4.1 Allocation to experimental and control groups In this process a single group is allocated into two subgroups at random. The assumption is that the control variables will also be randomised. In other words, the effect of the control variables will be purely random. If the two samples show a statistically significant difference (see Section 8.3.12.11)i n the dependent variable then it is assumed that this is due to the experimental stimulus and not the randomised control variables. There are two major problems with this approach. First, it is not always possible to allocate a sample into two random subgroups. Second, randomisation of control variables may not be achieved if the sample groups are small; and this procedure should only be used when there is an initial sample of about one hundred people. The other way of getting a control group is by using matched pairs. In this procedure relevant control factors are identified. Then for every person allocated to the experimental group, a person with the same set of values of the control variable is allocated to the control group. For example, gender, age and ethnicity might be important control factors in an experiment. So, if an 18-year-old white woman was allocated to the experimental group then a matching 18-year-old white woman would also need to be allocated to the control group. There are several problems with this procedure. First, you have to decide on the important control variables. The more you have, the more difficult it will be to match people. Second, this approach is likely to be wasteful because you are unlikely to be able to match all the people in your original sample. Third, if someone drops out of one group during a test-retest design, then you have to disregard the results of the matching person in the other group. In general, it is preferable to match the control and experimental groups but also to allocate the pairs into the two groups at random. This way, control variables that you had not considered are likely to be randomly allocated. In the suggested risky shift experiment (see answer to Activity 9.1, part 3) a randomised allocation was suggested. As the 'risky shift' notion does not specify any other factors that are likely to have a bearing then it is difficult to determine other control variables for purposes of matching. An experiment reported by Dixon et al. (1987) illustrated the steps in the experimental approach (CASE STUDY Healthy snacks). 9.1.5 Epistemology of the classic experiment In effect, an experiment occurs at a late stage of the research and is a practical test of a causal theory. The researcher, by using the experiment, hopes to prove or disprove a hypothesis. Proof refers to the evidence that is collected and presented to establish a causal relationship rather than just a chance happening. The idea of proof contains the notion that there are 'objective' facts that can be verified using scientific methods borrowed from the natural sciences. Thus, the experiment is the ultimate positivist research design. Survey research that adopts multivariate analysis attempts to reproduce the experimental approach. It does this not by physically controlling factors, as in the experiment, but by taking account of control variables when showing relationships between independent and dependent variables. Although the experiment is the 'classic' positivistic approach, it has limited application in the social sciences, even for positivists. The aim of experiments is to allow a researcher to examine the effect that a change to one variable has upon another. In other words, to put the researcher in a position where she or he can be in control of all the variables and be able to measure and study them and their effect. The problem in the social sciences is that the researcher is unlikely either to be able to manipulate the independent variable or to control for all other relevant factors. In practice, psychologists are more likely to use experiments than are other social scientists. Laboratory-type experiments are often used to simulate a situation to assess subjects' psychological reactions. For example, Haney et al. (1973) looked at the effect on individuals when they were given the role of either prisoner or guard in a simulation prison. Similarly, in 1961, Albert Bandura carried out a psychological experiment. He showed children an adult beating up an inflatable doll, then left each child with the doll to see what he or she would do. The children also threw punches at it. He concluded that we are inclined to copy violent behaviour, rather than find it cathartic. In an experiment in 1986, designed to test reactions to pornography, Neil Malamuth and Joseph Ceniti recruited 42 male college students and assessed them on the 'likelihood of rape' scale. Then he divided them randomly into three groups. The first was given a selection of sexually explicit materials containing scenes of rape and sadomasochism. The second was given non-violent pornography. The third group, the control group, was given non-pornographic material. Participants were studied over a 4-week period and were exposed to the media on ten separate occasions. In what the subjects thought was an unrelated experiment a week later, each of the men was paired up with a woman and told that she was not attracted to him. Then they had to play a guessing game, with the man having an option to punish the woman each time she got the answer wrong. The authors stated there was no difference in proclivity to rape between those exposed to the violent versus non-violent pornography, or the non-pornographic media. There were also no significant effects found over the desire to hurt females. In conclusion, neither violent nor non-violent pornography viewed over time, affected aggressiveness toward females or the likelihood to rape. From this and many other similar experiments, Malamuth and Ceniti (1986) concluded that if a man is already sexually aggressive and consumes a lot of sexually aggressive pornography, there is a greater likelihood that he will commit a sexually aggressive act. The authors thus argued against the simplistic thesis that pornography leads to rape, suggesting instead that, for some people, it may be viewed as a positive aspect of their life and does not lead them in any way to engage in any form of anti-social behaviour, while for others who have several other risk factors it can be a contributing factor towards violent activity. 9.1.6 Reliability of the classic experiment The Hawthorne studies showed that people under observation do not behave normally but respond to experimental conditions, not the experimental stimulus. In the study at the Hawthorne Works, the workers increased productivity even when their work conditions had worsened. They worked harder because of what they saw as the interest shown in them by the researcher and because they though the experiment would somehow lead to better working conditions in the factory. Thus they ignored the experimental stimulus and simply went on producing more because they were in an experimental situation. This reaction to the experimental situation undermines the measurements made. Instead of having an unreliable measuring device the measurements are unreliable because the context in which they are made keeps changing. In short, the meaning of measurements keeps changing even though the 'objective' measure is consistent. It thus questions the reliability of the outcomes of experiments involving human subjects. 9.1.7 Validity of the classic experiment The internal validity of the research can only be called into question if the design is faulty, or the means of controlling other factors is inadequate. In practice, of course, design and control are a problem, which is the main reason why experiments are not often used by sociologists. The unreliability (see Section 1.9) of some experiments is due to the problem of controlling for the impact of the experiment itself. Experiments are regarded as having poor external validity (see Section 1.8.2.5). External validity refers to the applicability of the results in different circumstances. Experimental results in the social sciences are often regarded as having very little relevance for the natural setting outside the experiment (ecological validity (see Section 1.8.2.6)). To what extent would the experimental sample of betting-shop punters make the same decisions if they were wagering their own money in a betting shop? Would Haney's experimental prison guards still like the role if it wasn't a simulated prison? Similarly, are the effects noted as the result of an experiment long term or short term? Experiments that attempt to show the effects on subjects of televised violence have been criticised for assuming that immediate reactions are the same as long-term effects. External validity also relates to the extent to which experimental results can be generalised to a broader population (population validity). An experiment might work on a group of psychology students but does this mean that the results can be generalised to all students, or the whole population? If you are going to make claims about the population then you must conduct the experiment on a representative sample. Christopher Ferguson and Richard Hartley, (2009, p. 326) sum up the problems in relation to studies of the effect of pornography:
Suggested answer to Activity 9.1 part 3: A suitable design for the 'risky shift' experiment would be to ask a sample of punters to select the winners from a racecard of six races. The sample would be divided into two groups at random. The first group to make betting selections singularly, the second group to be divided into subgroups of five individuals and asked to make their decisions as a group. Riskiness would be judged by the combined odds of the selections made by each individual or subgroup. The average odds for the two samples would be tested to see if they were significantly different.
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