What are the types of reliability?
test-retest
internal consistency
split-half
What does test-retest reliability measure?
the consistency of your measurement, or the degree to which an instrument measures the same way each time it is used under the same conditions with the same participants
What is internal consistency?
the inter-scorer reliability which is the correlation between two or more raters who rate the same item
What is split-half reliability?
split the questionnaire in half and determine the correlation between the responses to each half
What is the function of Cronbach’s Alpha and how does it work?
calculates the reliability of a scale by splitting the questions on the scale every possible way and computes the correlations - the average of these correlations is alpha
What are the acceptable values for Cronbach’s Alpha?
anything above .70 is acceptable
needs to be used with caution
What is the inter-item reliability index?
the correlation between the score on the item and the score on the scale as a whole; items
