Reliability/Validity

• What is reliability in psychology?

  A measure of consistency
• How is inter-observer reliability assessed?


  By correlating the observations or scores of two or more observers
• What correlation coefficient indicates reliability in inter-observer reliability?

  +0.8 or higher
• What does test-retest reliability involve?

  The same people repeating a measure on different occasions
• What correlation coefficient indicates reliability in test-retest reliability?

  +0.8 or above
• What is validity in psychology?

  The extent to which something is true or legitimate
• What is internal validity?


  Whether a researcher measures what he/she intended to
• What is external validity?


  Whether results can be generalized outside of the sample or situation
• What is face validity?


  Does the test appear to measure what it says it measures?
• What is concurrent validity?

  The performance of the test is compared to a recognized test in the same field
• How can reliability be improved in questionnaires?


  • Change open questions to closed questions to minimize ambiguity
• How can reliability be improved in interviews?

  • Ensure the same interviewer conducts all interviews
  • Provide training to limit potential bias
• How can reliability be improved in experiments?

  • Increase control over extraneous variables
• How can reliability be improved in observations?


  • Operationalize behavioral categories
  • Ensure there is no overlap between categories
• How can validity be improved in experiments?

  • Use control groups to see the impact of an independent variable
  • Implement standardized instructions and procedures
  • Use single-blind and double-blind procedures

  
• How can validity be improved in questionnaires?

  • Include lie scales to check for consistency
  • Use two questions that ask the same thing in opposite ways
• How can validity be improved in observations?

  • Use covert observations to reduce bias
  • Use operationalized behavioral categories that do not overlap