laboratory experiments

what are laboratory experiments?

studies that aim to establish a cause and effect relationship between an IV (which is changed by the researcher) and a DV (which is measured). they are conducted in a controlled environment using standardised procedures

2 advantages of a laboratory experiment

high degree of control over variables, easy to replicate

high degree of control over variables

research is conducted in the controlled setting of a laboratory which allows extraneous variables to be controlled e.g. the lighting, temperature and noise levels can be standardised. this is a strength as the research will measure what it intends to measure giving it high internal validity

easy to replicate

research conditions are carefully controlled, the conditions used for one study can be easily repeated in future replications of the study. for example, the same noise levels, lighting and temperature can be achieved time and time again. this is positive as it means the findings can easily be tested for reliability (i.e. test retest method)

two disadvantages of a laboratory experiment

high demand characteristics, low ecological validity

high demand characteristics

this means that the scientific setting of the laboratory means that participants are aware they are taking part in research which may cause them to change their behaviour in some way. for example, participants may work out the aim of the research and start behaving differently to give the researcher the results they think they want. this is a problem as it means the study is not measuring their true behaviour which lowers the study’s internal validity

low ecological validity

this means that the research takes place in the artificial setting of a laboratory so it may not reflect the participants’ natural behaviour in the real world. for example, participants may behave differently to the way they would behave in the street, at home or at work. this is problematic because the findings cannot be generalised to real-life settings