vlaidity

• what is content validity


  does the test include everything it needs to meet the aim
• concurrent validity 


  this is a way of assessing external validity by comparing new test with an already existing test
• construct validity 


  the degree to which the instrument used is measuring the characteristic
• face validity 


  does the test measure what it intended to measure
• predictive validity 


  correlating results with another similar test that is looking at the same behaviour