To what extent can we generalise the findings to differentgroups of people, situations, and measures
3types of external validity
Population
Ecological
Historical
Population Validity
is the sample group representative of the gen pop? is the sample biased? can results be generalised?
If results can't be generalised to larger pop = lack pop validity
Ecological Validity
if study have eco validity = generalise findings from research settings to real life situations. when research conducted in realistic, natural enviro = high eco validity. low mundane realism = low eco validity (vice-versa)
Historical Validity
can results be generalised to different time periods?
