Experiments Flashcards
Experiments definition…
Experiments aim to measure the effect which an independent variable (the ’cause’) has on a dependent variable (‘the effect’).
The key features of an experiment are control over variables, precise measurement, and establishing cause and effect relationships.
In order to establish cause and effect relationships, the independent variable is changed and the dependent variable is measured; all other variables (known as extraneous variables) are controlled in the experimental process.
What are the three types of experiments?…
> Laboratory Experiments take place in an artificial, controlled environment such as a laboratory.
> Field Experiments – take place in a real world context such as a school or a hospital.
> The comparative method – involves comparing two or more similar societies or groups which are similar in some respects but varied in others and looking for correlations. Think of Murdock.
Experiments…
Experiments aim to measure the effect which an independent variable (the ’cause’) has on a dependent variable (‘the effect’).
The key features of an experiment are control over variables, precise measurement, and establishing cause and effect relationships.
In order to establish cause and effect relationships, the independent variable is changed and the dependent variable is measured; all other variables (known as extraneous variables) are controlled in the experimental process.
Hypothesis…
Experiments typically start off with a hypothesis which is a theory or explanation made on the basis of limited evidence as a starting point for further investigation.
A hypothesis will typically take the form of a specific, testable statement about the effect which one or more independent variables will have on the dependent variable.
Hypothesis confirmed…
Having collected the results from the above experiment, you might reasonably hypothesise that Singing twinkle, twinkle little star to a rose plant three times a day, increases plant growth by 15cm a plant. When compared to a plant that doesn’t get sung to.
Objectivity…
Experiments are that they are supposed to produce objective knowledge – that is they reveal cause and effect relationships between variables which exist independently of the observer, because the results gained should have been completely uninfluenced by the researcher’s own values.
In other words, somebody else observing the same experiment, or repeating the same experiment should get the same results. If this is the case, then we can say that we have some objective knowledge.
Pros of experiments…
It allows us to establish ’cause and effect relationships’ between variables.
It allows for the precise measurement of the relationship between variables, enabling us to make accurate predictions about how two things will interact in the future.
The researcher can remain relatively detached from the research process, so it allows for the collection of objective knowledge, independent of the subjective opinions of the researcher.
It has excellent reliability because controlled environments allow for the exact conditions of the research to be repeated and results tested.
Cons of experiments…
There are so many variables ‘out there’ in the real world that it is impossible to control and measure them all.
Most social groups are too large to study scientifically, you can’t get a city into a laboratory to control all it’s variables, you couldn’t even do this with a field experiment.
Human beings have their own personal, emotionally charged reasons for acting, which often they don’t know themselves, so they are impossible to measure in any objective way.
Human beings have consciousness and so don’t just react in a predictable way to external stimuli: they think about things, make judgements and act accordingly, so it’s impossible to predict human behaviour.
There are also ethical concerns with treating humans as ‘research subjects’ rather than equal partners in the research process.
Why a lab experiment?…
> Accuracy and Precision– Laboratory experiments allow the precise effects of independent variables on dependent variables to be measured. This in turn makes it possible to establish cause and effect relationships between variables.
> Isolation of Variables – The controlled conditions of laboratory experiments allows researchers to isolate variables more effectively than with any other research method.
> Reliability - the controlled environment means it easy to replicate the exact environmental conditions of the original experiment and this also means it is relatively easy for the researcher to clearly outline the exact stages of the experiment, again making exact replication easier.
> Reliability and detachment - here is a high level of detachment between the researcher and the respondent. In an experiment, the researcher typically takes on the role of ‘expert’ and simply manipulates variables, trying to have as little interaction with the respondents as the experiment will allow for.
Practical advantages of lab experiments…
Practical advantages experiments (assuming they are ethical) are attractive to funding bodies because of their scientific, quantitative nature, and because science carries with it a certain prestige.
Once the experiment is set up, if it takes place in a lab, researchers can conduct research like any other day-job – there is no travelling to visit respondents for example, everyone comes to the researcher.
Ethical issues surrounding lab experiments…
While some laboratory experiments are notorious for their ethical problems, it is at least usually obvious that research is taking place (even if the exact purpose of the research may be hidden from respondents). Also, the benefits to society might well outweigh the costs to respondents.
Deception and lack of informed consent are an ethical problem.
It is often necessary to deceive subjects as to the true nature of the experiment so that they do not act differently, meaning that they are not in a position to give full, informed consent. This was the case in the Milgram experiment, where the research subjects thought the (invisible) person receiving the shocks was the actual subject rather than themselves.
A second ethical problem concerns harm to respondents.
In the case of the original Milgram experiment, ‘many research participants were observed to sweat, stutter, tremble, bit their lips and dig their nails into their flesh, full-blown, uncontrollable seizures were observed for three subjects’.
Practical issues surrounding lab experiments…
Practical problems include the fact that you cannot get many sociological subjects into the small scale setting of a laboratory setting. You can’t get a large group of people, or a subculture, or a community into a lab in order to observe how the interact with ‘independent variables’.
Also, the controlled nature of the experiment means you are likely to be researching one person at a time, rather than several people completing a questionnaire at once, so it may take a long time to get a large-sample.
Theoretical issues surrounding lab experiments…
Laboratory experiments lack external validity – sociologists hardly ever use lab experiments because the artificial environment of the laboratory is so far removed from real-life that most Sociologists agree that the results gained from such experiments tell us very little about how respondents would actually act in real life.
Choosing field experiments instead…
> Better external validity – The big advantage which field experiments obviously have better external validity than lab experiments, because they take place in normally occurring social settings.
> Larger Scale Settings – Practically it is possible to do field experiments in large institutions – in schools or workplaces in which thousands of people interact for example, which isn’t possible in laboratory experiments.
Possible issues with field experiments…
It is not possible to control variables as closely as with laboratory experiments – With the Rosenthal and Jacobson experiment, for example we simply don’t know what else might have influenced the ‘spurting group’ besides ‘higher teacher expectations’.
Still the same problem with the Hawthorne effect.
Access is likely to be more of a problem with lab experiments. Schools and workplaces might be reluctant to allow researchers in.
It is often possible to not inform people that an experiment is taking place in order for them to act naturally, so the issues of deception and lack of informed consent apply here too, as does the issue of harm.
