Validity and Reliability

• Reliability​

  Reliability is when you can repeat an experiment to establish consistent findings​
• Applied reliability​

  Have the same list of symptoms, will make a consistent diagnosis when diagnosis is repeated​
• Inter-rater reliability​

  When 2 or more different clinicians diagnose the same patient with the same disorder​
• Test-retest reliability​

  Assess the same patient 2 or more times and see whether they receive the same diagnosis​
• Validity​

  The extent to which a test measures what it is supposed to​
• Applied validity​

  Assess the patients symptoms and makes an accurate diagnosis​
• Concurrent validity​

  If you compare the diagnosis of one diagnostic manual with one that's already found to be valid, and the same diagnosis is given to the patient.​
• Predictive validity​

  Diagnosis is valid if it predicts the course of the illness accurately; prediction of future behaviour caused by the disorder (recovery possible?, symptoms continue?, treatment effective?)​
• Construct validity​

  The extent to which the symptoms listed for diagnosis are representative enough to measure what they are supposed to be measuring.​