reliability + validity
Cards (9)
- reliability:
- how consistent the findings from the investigation/ measuring device are
- measuring device - reliable if produces consistent results everytime its used
- reliability of observational techniques:
- assessing - repeat observation e.g rewatching + inter rate reliability - comparing with observer
- improving - behavioural categories have to be operationalised, observers need to be equally experienced
- graph - observer a on x axis, b on y (scattergram = +0.8 good reliability)
- self report techniques:
- assessing - test/retest reliability e.g give test again, inter-interviewer reliability e.g extent to which interviewers agree
- improving - reduce ambiguity e.g rewrite questions, use same interviewer each time + good training to reduce leading questions
- experiments:
- DV often measured using rating scale/ behavioural categories - method used to measure should be consistent
- improving - standardisation, instructions, procedures same each time, experiment is repeated then compared
- validity:
- producing a result that is legitimate
- internal - study measures what its meant to measure
- external - findings can be generalised beyond research setting
- factors that affect internal validity:
- investigator effects
- not operationalised
- cofounding variables
- social desirability bias
- demand characteristics
- ecological validity:
- to do with how DV is measured
- example: field experiment godden + baddeley learning word lists - low mundane realism + aware theyre being assessed low ecological validity
- assessing validity:
- face validity - extent to which test items look like what the test is meant to measure
- concurrent validity - comparing existing method/test with the one you want to use e.g existing questionnaire, one you want to use
- improving validity:
- poor face validity - rewrite questions, poor concurrent - remove irrelevant questions
- demand characteristics + investigator effects - double blind
- experiment - control group + standardisation
- questionnaires - anonymity, no social desirability bias
- observations - covert + behavioural categories operationalised
- triangulation - number of different sources used as evidence