METHODS - validity and reliability Flashcards
what is reliability
reliable if measurement is repeated and the same result is obtained
test-retest
same test/questionnaire is given to the same people on 2 or more different occasions
if it’s reliable the test/questionnaire results should be the same or very similar both times
inter-observer
2 or more observers compare their data by conducting a pilot study to check that they are applying behavioural categories in the same way
should watch the same event but record data independently
correlation coeffiecient should
exceed +0.8 for it to be reliable
questionnaires (improve reliability)
rewrite or deselect questions
replace open question with closd, less ambiguous questions
interviews IR
all interviewers must be trained
use the same interviewer the whole time
experiments IR
standardised procedures
observations IR
behavioural categories shoulld be measurable
they shouldn’t overlap
all behaviours included
may end up with inconsistent records if they have to use their own judgemet to decide what to record and when if categories not good
what is validity
whether an observed effect is genuine and represents what is actually ‘out there’ in the real world
how can something be reliable but not valid
consistent findings but not measuring what it’s supposed to
ecological validity
whether findings can be generalised from one setting to another
may not be related to the setting but the task
temporal validity
findings should be consistent over time
face validity - assessing validity
does the test measure what it’s supposed to measure
concurrent validity - assessing validity
whether findings are similar to those on a well-established test
experiments - improving validity
control group - more confident that changes in the DV were due to the effect of the IV
standardised procedures - minimise the impact of participant reactivity and investigator effects
