Reliability

• Split-half Method Reliability


  Compare half of the questions with the other half to check for consistency of difficulty

  • Internal Reliability
• Test-retest Reliability 


  An assessment of the consistency of a psychological test or questionnaire to see how similar scores/responses are when a person is tested twice

  • External Reliability
• Replication Reliability 


  An experiment should produce the same results if the same standardised procedures are used

  • External + Internal Reliability
• Inter-rater/observer Reliability 


  An assessment of the extent to which two or more ratings/observations of the same behaviour are consistent

  • External Reliability
• Internal Reliability 


  How consistently different items within a test measure the same concept or construct. It ensures that a test is stable across its components.
• External Reliability 


  How consistently a test produces similar results over repeated administrations or under different conditions. It ensures that a test is stable over time and situations.