reliability Flashcards
reliability
measure of consistency
ways of assessing reliability - test-retest
test-retest method
administering the same test or questionnaire to the same perosn on different occasions
if the test is reliable then the results obtained should be the same or similar each time
must be sufficient time between the test and retests to ensure that the paritpant/respondent cannot recall their answrtes to the questionnaire or test
two sets of scores would be correlated to make sure they are similar
if correlations turns out to be significant then the reliability of the measuring instrument is assumed to be good
ways of assessing reliability
everyone has their own unique way of seeing the world
observers interpretation of events may differ widely for someone else’s - introduces subjectivity bias and unreliability into the data collection process
instead conduct their observation in teams of at least two
inter-observer reliability must be established
may involve small scale trial run (pilot study) - to check that the observers are applying behavioural categories in the same way
data collected by the two observers should be correlated to assess its reliability
measuring reliability
correlation analysis
the correlation co efficient should exceed +.80 for reliability
improving reliability - questionnaires
a questionnaire that produces a low-test-retest reliability may require some of the items to be deselected or rewritten
solution may be to replace some of the open questions with closed fixed choice alternatives which may be less ambiguous
improving reliability - interviews
use the same interviewer each time
interviewers must be properly trained if this can’t happen
dont ask to leading or ambiguous questions
more easily avoided in structured interviews where the interviewers behaviour is more controlled by the fixed questions
interviews that are unstructed and more free-flowing are less likely to be reliable
improving reliability - observations
can be improved by making sure that behavioural categories have been properly operationalised and that they are measurable and self-evident
categories should not overlap and all possible behaviours should be covered on the checklist
improving reliablity - experiments
procedures must be consistent every time
therefore in terms of reliability an experimenter is concerned about standardised procedures
