reliability Flashcards
what is reliability?
reliability is a measure of consistency. a measuring device is said to be reliable if it produces consistent results every time it is used.
what are ways of assessing reliability?
test-retest reliability (self-report techniques)
inter-observer reliability (observational techniques)
self report techniques
what is test-retest reliability?
a method of assessing the reliability of a questionnare or psychological test by assessing the same person on two separate occassions. this shows to what extent the test produces the same answers.
most commonly used with questionnares, and psychological tests such as iq, but can be also applied to interviews.
what happens in the case of a questionaire or test?
the two sets of scores are correlated to make sure they are similar. if the correlation turns out to be significant then reliability of the measuring instrument is assumed to be good.
how can we improve reliability in a psychological test?
reduce ambiguity; low reliability in a psychological test may be because some test items are ambiguous so people give different answers. in such cases, test items need to be re-examined and re-written.
what is inter observer reliability?
the extent to which there is agreement between two or more observers involved in observation of a behaviour. it is measured by correlating the observations of two or more observers.
how can we improve reliability in observations?
behavioural categories; making sure that behavioural categories have been operationalised, and that they are measurable and self-evident.
if categories are not operationalised well, or are overlapping or absent, different observers have to make their own judgements of what to record, proving inconsistent records.
how can we improve reliability in an experiment?
using a lab experiment. the researcher can exert strict control over many aspects of the procedure, such as the instructions that participants receive and the conditions within which they are tested. certainly such control is often more achievable in a lab than in a field.
II
standardisation; procedures are often repeated for different participants thereforeit is important that the procedures are exactly the same each time because otherwise we cannot compare the performance of participants. for this reason, procedures are standardised.
