Reliability

• Reliability:

  • The consistency or repeatability of a measure
  • NOTHING is 100% reliable
• Types of Reliability:

  • Intra-rater reliability:
  • Degree of consistency of a set of measures taken by the same person
  • Inter-rater reliability:
  • Degree of consistency in the measures taken by 2 or more people
  • Instrument reliability - inter/intra:
  • The degree of consistency associated with the specific measurement too
• Test Accuracy:

  • Classification Accuracy:
  • how well a test correctly identifies or excludes a condition
  • Sensitivity:
  • how well a test correctly identifies a condition
  • Specificity:
  • how well a test correctly excludes a condition
• • Sensitivity= Number of people correctly identified as having an ACL rupture/all people with an ACL rupture
  • i.e. Sensitivity = True positives/(true positives + false negative)
  • Specificity = People correctly identified as not having an ACL rupture /All people without an ACL rupture
  • i.e. Specificity = True negatives/(false positives + true negatives)
  • Classification accuracy = People with and without ACL rupture correctly identified/All people who were tested
  • i.e. Classification Accuracy = True positives + true negatives/(positives + negatives)