Definitions, key features and the theoretical, practical and ethical strengths and limitations of laboratory and field experiments applied to sociology (and psychology). Also covers key terms related to experiments
Experiments – The Basics: Definitions/ Key Features
- Experiments aim to measure the effect which one or more independent variables have on a dependent variable.
- The aim is to isolate and measure as precisely as possible the exact effect independent variables have on dependent variables.
- Experiments typically aim to test a ‘hypothesis’ – a prediction about how one variable will effect another.
- There are two main types* of experimental method: The Laboratory experiment, the field experiment and the comparative method.
- 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.
Advantages of Laboratory Experiments
- Theoretical – The controlled conditions of laboratory experiments allow researchers to isolate variables: you can precisely measure the exact effect of one thing on another.
- Theoretical – You can establish cause and effect relationships.
- Theoretical – You can collect ‘objective’ knowledge – about how facts ‘out there’ affect individuals.
- Theoretical – Good Reliability because it is easy to replicate the exact same conditions.
- Theoretical – Good Reliability because of the high level of detachment between the researcher and the respondent.
- Practical – Easy to attract funding because of the prestige of science.
- Practical – Take place in one setting so researchers can conduct research like any other day-job – no need to chase respondents.
- Ethical – Most laboratory experiments seek to gain informed consent, often a requirement to get funding.
- Ethical – Legality – lab experiments rarely ask participants to do anything illegal.
- Ethical – Findings benefit society – both Milgram and Zimbardo would claim the shocking findings of their research outweigh the harms done to respondents.
Disadvantages of Laboratory Experiments
- Theoretical – They are reductionist: human behaviour cannot be explained through simple cause and effect relationships (people are not ‘puppets’).
- Theoretical – Laboratory experiments lack external validity – the artificial environment is so far removed from real-life that the results tell us very little about how respondents would actually act in real life.
- Theoretical – The Hawthorne Effect may further reduce validity – respondents may act differently just because they know they are part of an experiment.
- Theoretical – They are small scale and thus unrepresentative.
- Practical – It is impractical to observe large scale social processes in a laboratory – you cannot get whole towns, let alone countries of people into the small scale setting of a laboratory.
- Practical – Time – Small samples mean you will need to conduct consecutive experiments on small groups if you want large samples, which will take time
- Ethical – Deception and lack of informed consent – it is often necessary to deceive subjects as to the true nature of the experiment so that they do not act differently. Links to the Hawthorne Effect.
- Ethical – Some specific experiments have resulted in harm to respondents – in the Milgram experiment for example.
- Ethical – Interpretivists may be uncomfortable with the unequal relationships between researcher and respondent – the researcher takes on the role of the expert, who decides what is worth knowing in advance of the experiment.
Advantages of Field Experiments over Laboratory Experiments
- Theoretical – They generally have better validity than lab experiments because they take place in real life settings
- Theoretical – Better external validity – because they take place in normally occurring, real-world social settings.
- Practical – Larger scale settings – you can do field experiments in schools or workplaces, so you can observe large scale social processes, which isn’t possible with laboratory experiments.
- Practical – a researcher can ‘set up’ a field experiment and let it run for a year, and then come back later.
The relative disadvantages of Field Experiments
- Theoretical – It is not possible to control variables as closely as with laboratory experiments – because it’s impossible to observe respondents 100% of the time.
- Theoretical – Reliability is weaker – because it’s more difficult to replicate the exact context of the research again.
- Theoretical – The Hawthorne Effect (or Experimental Effect) may reduce the validity of results.
- Practical Problems – access is likely to be more of a problem with lab experiments. Schools and workplaces might be reluctant to allow researchers in.
- Ethical Problems – As with lab experiments – 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.
Experiments – Key Terms Summary
Hypothesis – 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 testable statement about the effect which one or more independent variables will have on the dependent variable.
Dependent Variable – this is the object of the study in the experiment, the variable which will (possibly) be effected by the independent variables.
Independent variables – The variables which are varied in an experiment – the factors which the experimenter changes in order to measure the effect they have on the dependent variable.
Extraneous variables – Variables which are not of interest to the researcher but which may interfere with the results of an experiment
Experimental group – The group under study in the investigation.
Control group – The group which is similar to the study group who are held constant. Following the experiment the experimental group can be compared to the control group to measure the extent of the impact (if any) of the independent variables.
You should also know about natural experiments/ the comparative method –involves comparing two or more societies or groups which are similar in some respects but varied in others, and looking for correlations.
These are the more in-depth posts…