validity

• internal validity


  refers to the design of the research and whether it is measuring what it thinks it is measuring

  • whether the effects observed in a study are due to the manipulation of the independent variable and not some other factor. (there is a causal relationship between the independent and dependent variable)( e.g. extraneous variables, demand characteristics, order effect)

  types:

  • face validity
  • content validity
• external validity


  • refers to how 'true' a picture the findings are giving

  3 types:

  • ecological validity
  • population validity
  • temporal validity
• ecological validity


  the findings reflect real life.

  • if it lacks ecological validity, it is usually because it has been carried out in a lab (artificial environment), not reflecting real life behaviour/situations)

  to ensure ecological validity, carry your research out in a real life setting (not a lab)
• population validity


  refers to who is being studied

  • if the sample is representative, study will have greater population validity
• temporal validity


  refers to the time when a study was carried out

  • if it was a long time ago then things may have changed
• face validity


  refers to using a common sense way of measuring something

  • it can also involve asking people if they think it is a good way of measuring something, and that is an accurate measure
• content validity


  refers to an expert checking the research design and checking it is measuring what it intends
• affecting validity


  • demand characteristics
  • extraneous and confounding variables
  • order effect (fix by counterbalancing)
  • double blind technique (improves validity)
• concurrent validity


  refers to how a newly designed test compares with an established test.

  • if results are similar them it has concurrent validity (can check for the positive correlation)
• predictive validity


  refers to whether a newly designed test, accurately predicts results in the future