Experiments
Lab - These are conducted under controlled conditions, in which the researcher deliberately
changes something (I.V.) to see the effect of this on something else (D.V.).
STRENGTHS
Control – lab experiments have a high degree of control over the environment & other
extraneous variables which means that the researcher can accurately assess the effects of the
I.V, so it has higher internal validity.
Replicable – due to the researcher’s high levels of control, research procedures can be
repeated so that the reliability of results can be checked.
LIMITATIONS
Lacks ecological validity – due to the involvement of the researcher in manipulating and
controlling variables, findings cannot be easily generalised to other (real life) settings, resulting
in poor external validity.
Lacks mundane realism - artificial settings and unfamiliar environments may not reflect real life.
Demand characteristics - participants know they are being studied and want to help the
researcher to achieve goals for the experiment.
Field - These are carried out in a natural setting, in which the researcher manipulates
something (I.V.) to see the effect of this on something else (D.V.). E.g street, school
STRENGTHS
High ecological validity – field experiments have some degree of control but also are conducted
in a natural environment, so can be seen to have reasonable internal and external validity.
Less demand characteristics
LIMITATIONS
Less control than lab experiments and therefore extraneous variables are more likely to distort
findings and so internal validity is likely to be lower.
Lab - These are conducted under controlled conditions, in which the researcher deliberately
changes something (I.V.) to see the effect of this on something else (D.V.).
STRENGTHS
Control – lab experiments have a high degree of control over the environment & other
extraneous variables which means that the researcher can accurately assess the effects of the
I.V, so it has higher internal validity.
Replicable – due to the researcher’s high levels of control, research procedures can be
repeated so that the reliability of results can be checked.
LIMITATIONS
Lacks ecological validity – due to the involvement of the researcher in manipulating and
controlling variables, findings cannot be easily generalised to other (real life) settings, resulting
in poor external validity.
Lacks mundane realism - artificial settings and unfamiliar environments may not reflect real life.
Demand characteristics - participants know they are being studied and want to help the
researcher to achieve goals for the experiment.
Field - These are carried out in a natural setting, in which the researcher manipulates
something (I.V.) to see the effect of this on something else (D.V.). E.g street, school
STRENGTHS
High ecological validity – field experiments have some degree of control but also are conducted
in a natural environment, so can be seen to have reasonable internal and external validity.
Less demand characteristics
LIMITATIONS
Less control than lab experiments and therefore extraneous variables are more likely to distort
findings and so internal validity is likely to be lower.
