experiments Flashcards
laboratory experiments features
- carried out in a controlled environment
- IV is directly under the experimenter’s control and can be directly manipulated
- participants can be randomly allocated to conditions
field experiments features
- carried out in a natural environment
- Iv is under the experimenter’s control and can be directly manipulated
- participants can be randomly allocated to conditions
natural experiments features
type of quasi-experiment
- carried out in a natural or controlled environment
- make use of naturally occurring differences in the IV, which is not manipulated by the experimenter
- participants cannot be randomly allocated to conditions
quasi experiments
can be like any other type of experiment apart from: participants cannot be randomly allocated to conditions
quasi strengths and limitations
depend on the procedure of the study itself (eg if the procedure is set in a controlled environment with direct control over the IV, it’s likely to share many strengths or limitations with a lab experiment)
lab strengths e
unlike natural experiements (which make use of naturally occuring changes in the variables), lab experiments have high levels of control over extraneous and confounding variables that may affect the DV, increasing the internal validity of research.
this is due to lab experiments being performed in highly controlled settings which means the impact of these unwanted variables can be minimised.
lab strength c
unlike natural experiments (which make use of naturally occurring changes in variables), a strength is that it is possible to establish cause and effect
which is when it is possible to establish a casual relationship between the IV and DV
this is because the IV is directly manipulated by the experimenter to record its effect on the DV
this means that, as the experiment takes place in a highly controlled setting, any change in the DV must be caused by the IV alone
lab limit l
unlike field experiments performed in real like settings, lab experiments have low mundane realism which is when the procedure is not mundane or like real life, decreasing external validity of the research
this is as they are performed in artificial and controlled settings meaning the results won’t reflect real life behaviour and cannot be successfully applied to other settings
lab limit h
they have high demand characteristics unlike field experiments where participants don’t know they are participating in a study
which is when participants perceive the demands of the study and act accordingly, lowering the internal validity of the research because of the chnage in their natural behaviour due to participants being informed that they are taking part in research
meaning it may be obvious what the experiment is about
field experiments strength h
they have high mundane realism unlike lab experiments which are performed in artificial and controlled settings
this means that the procedure is mundane or like real life, increasing the external validity of research
this is due to them being performed in real life settings
meaning the results will reflect real life behaviour and so can be successfully applied to other settings
field experiments strength l
unlike lab experiments (where they know they’re in a study), they have low demand characteristics
which is when the participants perceive the demands of the study and act accordingly, lowering the internal validity of the research because of the change in their natural behaviour
this is because field experiments are performed in a natural environment, often without participants knowing, meaning they only show natural behaviour
field experiments limitation e
limited control over extraneous and confounding variables, that may randomly or systematically affect the DV, decreasing the internal validity of research
this is due to field experiments being performed in real life settings not a controlled environment (which is the case in lab experiments), which means the impact of these unwanted variables cannot be easily minimised.
field experiments limitation 2
impossible to gain participants informed consent
which is when they are not made aware of the experiment’s aims, procedures and anticipated findings before agreeing to take part in a study
this is because field experiments are performed in a natural environment, often without the participants knowing that they are taking part in an experiment
meaning participants cannot make an informed decision about their participation
natural experiments strength p
unlike lab experiments (where research is performed in an artificial and controlled environment) allows us to investigate psychological phenomena where it would be unethical to investigate with direct manipulation of the IV (ie by causing an event )
this is because natural environments make use of a naturally occurring variation in the IV
for example, it would be unethical to cause brain damage to see its effects so we use naturally occurring cases of brain damage in our research
natural experiments strength h
unlike lab experiments (performed in artificial and controlled environments) they have high ecological validity which is when the findings can be successfully generalised to other real life settings, increasing the external validity of research
this is because they make use of a naturally occurring change in the IV meaning they reflect real life behaviour
