validity and reliability Flashcards
under issues in psychological research
validity def
the extend to which an observed effect is genuine- does it measure what is was supposed to measure, can it be generalised to outside the research setting
what is internal validity def
whether the researcher has managed to measure what they intent to measure
def of external validity
the extent to which findings can be generalised beyond the research setting in which they were found
how do you improve the validity of experiments
use a control group (so researcher can see if changed in dv were an effect of the iv)
used a standarised procedure eg single blind or double blind
how does a standardised procedure improve the validity of an exp
minimises the impact of participant reactivity and investigator effects on the validity of the outcome
what is a single blind procedure
participants are not made aware of the study aims until they have taken part to reduce demand characteristics
what is double blind technique
participants are not made aware of the study aims until they have taken part to reduce demand characteristics (same as single)
but a third party conducts the investigation without knowing its main purpose to reduce demand characteristics and investigator effects
how do you improve the validity of questionnaires (2)
incorporate a lie scale in order to assess consistency of a ps response and control effects of social desirability bias
ensure all ps that data submitted will be anonymous
how do you improve the validity of observations
make behaviour categories less broad, dont overlapp, be unambiguous,
eg dont have smiling and grinning
would already have high ecv as there is min intervention esp covert
When assessing the face validity of a test, we…
look at the test to see if it appears to measure what it claims to measure.
the test used to measure the dependent variable appears to measure what it claims to measure.
what is concurrent validity
the test used to measure the dependent variable gets similar results when compared to an older test measuring the same dependent variable.
what is replicability
the results of the study can be replicated because the method is clear.
We say that studies are reliable when…
the results of the study are CONSISTENT every time it is repeated.
what are the 2 things that make a study less reliable
extraneous variables that affect the measurements
The test or questionnaire used to measure the DV is itself unreliable.
what happens to a study if it lacks consistency in results
it lacks reliability
