This validity coefficient will be limited or attenuated by the reliability of the test or measure. Validity is often expressed as a correlation between the measure and some criterion. For example, a valid measure of suicide intention may not be particularly stable (reliable) over time though good at identifying those at risk of suicide. A measure of a characteristic which varies quite rapidly over time will not be reliable over time - if it is then we might doubt its validity. It also ought to distinguish between inventors and the rest of us if it is a valid measure of creativity. their creativity), a measure should be consistent over time (reliable). Where the measurement emphasis is on relatively stable and enduring characteristics of people (e.g. Be wary of statements which imply that a valid test or measure has to be reliable. Reliability and validity are, conceptually, quite distinct and there need not be any necessary relationship between the two. Reliability is generally thought to be necessary for validity, but it does not guarantee validity. Reliability and validity are important concepts within psychometrics. Relationship between reliability and validity 2 Relationship between reliability and validityīefore reading this section, make sure you understand:.
