validity

define validity

how accurately results reflect real world behaviour

what 4 things must you know validity for

• sampling methods (opportunity & stratified)

• experimental designs(repeated & independent)

• quantitative methods (lab experiment, field experiment)

• qualitative methods

explain validity in sampling methods

• do not always produce sample thats reflective of target pop

• opportunity sampling less likely to produce rep sample

• stratified more likely

explain validity in experimental designs

• repeated measures influenced by order effects= over come by counterbalancing

• independent affected by participant variable= overcome by random allocation

explain validity in quantitative methods

• lab experiments- involve artificial tasks/setting that arent reflective of real life , pp aware but greater control enhances validity

• field experiments -evs not controlled, tasks may be artificial, pp may be aware =reduce validity

• numerical data methods lack validity= reduce behaviour to a score

explain validity in qualitative methods

• greater validity -provide unrestricted info

• but data depends on subjective interpretation= reduces validity