Reliability is the extent to which a measurement tool is consistent.
- For a measurement tool to be reliable it would give you the same results if you tested the same person over a long period of time.
- In an observation reliability is achieved if several observers record the same behaviour.
Assessing Reliability
When assessing whether a study has reliability the following factors should be considered:
- Is there a standardised procedure/set of instructions?
- Is the study free from bias?
- Is there inter-rater reliability? (reliability between researchers)
- Has inter-rater reliability been tested?
- Is data interpretation standardised?
