Reliability

• saying results are reliable is another way of saying they are consistent, if the researchers replicate their study exactly, they will get similar results
• external reliability- the extent to which a measure is consistent when repeated eg the results of a study are consistent with an exact replication at a different time and/or with different participants
• internal reliability- the extent to which different parts of a measure are consistent with itself (if a 100 question IQ test is divided into two 50 second tests, the result for each set of questions with the same participant would be similar)
• test-retest- repeat the study using the same procedures/measuring devices at, different times and test the correlation between the two versions.
• inter-observer/inter-rater reliability- two (or more) observers record behaviours using the same behavioural categories; then, they test the correlation between each tally of behaviour to identify if the behavioural categories are appropriately operationalised.