A laboratory experiment takes place in a laboratory settings where there is high control over the variables and the partiipants have the ability to opt out of the experiment at any time. This could possibly interrupt the experiment.
An example of a laboratory experiment would come from Milgram (1974) with his experiment on electric shocks in which participants were asked to give the 'student' an electric shock when they got the question wrong.
Evaluation of laboratory experiments.
Establishes a cause and effect relationship between variables and the data is easy to analyse.
Allows for easy replication, making the results highly reliable and there is high ontrol over confounding variables.
These studies lack mundane realism and cannot be applied outside of the experiment due to the fact that participants could also lie as they know they are being watched, social desirability bias may occur and it is not a real life situation.
There are also ethical concerns due to the fact that the participant has the right to withdraw, yet this could highly impact the experiment.
These experiments are carried out in natural surroundings but there is control over the independant variable and also the allocation of participants to conditions.
These types of experiments are reasonably well controlled and can be replicated fairly easily with similar results.
Evaluation of field experiments.
Easy to establish a cause and effect relationship and easy to replicate the experiment, adding to the reliability of the experiment.
Higher external validity in comparison to a laboratory experiment due to the fact that participant behaviour is more typical of the natural setting.
There are ethical issues as there is a huge lack of informed consent and this could have implications for the data as participants can withdraw after being told the true nature of the experiment.
Low internal validity as there is less control than within a lab experiment and so although it could be replicated, the exact experiment would not gain the same results in the majority of cases.
This type of experiment makes use of naturally occuring events for research purposes. Although the independant variable is manipulated by the experimenter, there is no other interference and the experiment takes place in an ordinary situation.
An example of a natural experiment would come from Williams who researched in 1986, the effects of television on aggressive behaviour.
Evaluation of natural experiments.
Participants behave in a natural manner as they do not know they are being watched.
It can also investigate the effects of the independant variables that it would be unethical to manipulate,
The independant variable is not directly manipulated and therefore difficult to establish a cause and effect.
This also requires ethical sensitivity due to the fact that DIP may occur.
(Deception, Informed consent, Protection of participants.)