Scientists researching the natural sciences (physics, chemistry, biology) conduct their research in laboratories. In laboratories scientists are able to control the variables (e.g. temperature, light etc.) so an experiment can be undertaken in order to test out a hypothesis (a prediction which can be tested). The strength and weaknesses of the experimental method in sociology are:
The advantage of laboratory experiments are:
- makes isolating and manipulating variables easier so causes of events can be identified
- other scientists can easily repeat the same experiment
- they’re high in reliability as other researchers can replicate the same experiment and achieve the same results
- comparisons can be made with similar experimental research
- scientists can test their hypothesis in controlled conditions
By being in control of all the variables the scientist can adjust or isolate any variable in order to find out what might influence the hypothesis under scrutiny.
Let’s imagine that a scientist is conducting an experiment to test if light will result in more growth in salmonella in raw chicken than temperature.
In the laboratory the scientist could for example increase the amount of light (the independent variable is the variable that is manipulated by the researcher during an experiment) – in the laboratory to measure the effect of bright light on a piece of raw chicken in causing bacteria (the dependent variable is the bacteria growth) to flourish.
If nothing changes in the chicken the scientist might change the independent variable from light to room temperature while still keeping the dependent variable (the bacteria) the same.
Therefore in the next laboratory experiment the scientist increases the room temperature by 10 degrees and then measures the amount of salmonella now on the raw chicken. If there is a critical increase in the amount of salmonella bacteria the scientist can assume the temperature change (the independent variable) caused the number of bacteria (the dependent variable) to increase.
However in order to make certain it is the temperature and not the meat itself which could be the cause of the salmonella increase scientists, have a control group and an experimental group.
The researcher will take use two pieces of identical chicken one being named the control piece of chicken and the other the experimental piece of chicken. The scientist could increase the amount of light on the experimental group to see if the variable being investigated (the independent variable) changes compared to the control group. If light is seen to have no effect on the experimental group then that variable can be dismissed as a cause and the other variable such as temperature could be tested.
Using the objective procedures of the experimental method the researcher can eventually discover what causes salmonella bacteria to flourish as both groups were identical before the experiment and any subsequent changes could only have occurred by the changes imposed during the laboratory experiment.