Reliability and validity

• What is Reliability?


  Consistency
• What does Internal and External reliability mean?

  Internal reliability: Extent to which something is consistent within itself.

  External reliability: Extent to which the test measures consistently over time.
• What are the 2 types of internal reliability and what do they mean?


  • Split-half method: Compare half of the questions with the other half to check for similar levels of difficulty.
  • Inter-observer: Compare results from 2 different people.
• What are the 2 types of external reliability and what do they mean?

  • Test-retest method: Comparing results of the same questionnaire and the same person over a period of time.
  • Replication: Repeat an experiment to see whether the same results are produced (if correlation coefficient is +0.8, the results are considered reliable).
• Testing the reliability of...

  
• What is Validity?


  Accuracy
• What is Internal validity and External validity?

  Internal validity: Whether results obtained are solely affected by changes in the variable being manipulated (i.e., the independent variable) in a cause-and-effect relationship.

  External validity: A measure of whether the data can be generalised to other situations outside of the research environment.
• What are the 3 types of internal validity and what do they mean?

  • Face validity: A measure of whether it looks subjectively promising that a tool measures what it's supposed to.
  • Construct validity: Asks whether a measure successfully measures the concept it is supposed to.
  • Concurrent validity: Asks whether a measure is in agreement with pre-existing measures that are validated to test for the same [or a very similar] concept.
• What are the 3 types of external validity and what do they mean?

  • Ecological validity: Extent to which psychologists can apply their finding to other settings.
  • Temporal validity: Extent to which research findings can be applied across time.
  • Populational validity: Extent to which psychologists can generalise the findings from their sample to a larger group of people (the population).
• Testing the validity of...