reliability Flashcards
what is reliability?
refers to the consistency of findings from an investigation or measuring tool
what is test-retest reliability? (5)
● method of assessing the reliability of a questionnaire or psychological test (can also be used for interviews)
● the same person is assessed on two separate occasions
● two sets of scores are correlated to make sure they are similar
● shows to what extent the test produces the same answers (is consistent / reliable)
● if correlation is significant (and positive) then the reliability of measuring instrument assumed to be good
what is inter-observer reliability? (3)
● extent to which there is agreement between 2 or more observers involved in observation of behaviour
● check that observers are applying behavioural categories in the same way
● if correlation between observers is +80 then data has high inter-observer reliability
how to improve reliability in a questionnaire? (2)
● a questionnaire that produces low test-retest reliability may need some questions deselected / rewritten
● researcher may replace some open questions (which could be interpreted inconsistently) with closed questions that are less ambiguous
how to improve reliability in interviews? (2)
● to ensure reliability - use same interviewer
● if this is not possible, all interviewers must be trained so they ask same questions in the same way
how to improve reliability in observations? (2)
● behavioural categories should be operationalised and measurable, so they are less open to interpretation
● if this does not happen, different observers have to use their own judgement in deciding what to report and may end up with inconsistent results
how to improve reliability in experiments? (2)
● to compare the performance of different participants, the procedure must be the same each time
● therefore, standardised procedure should be used
