There are a lot of classes of Reliability Estimates. Some of the main ones are:
- Inter Rate Reliability: This kind of reliability assesses the degree of agreement that is there between two or more raters in their appraisals.
- Test Re test Reliability: This is used for assessing the degree to which these scores have consistency when shifted from one test administration to another one. The measurements are to be gathered from one single rater who puts to use the same methods or instruments in the same environment and conditions that were previously used for testing. This also includes the intra rater reliability.
- Inter Method Reliability: These test scores find out the degree to which these test scores have been consistent when there is a variation in the methods or instruments have been put to use. This gives way for removing the inter rater reliability
- Internal Consistency Reliability: This helps to assess the consistency in the results across the items that are there within the tests.
Link between Reliability and Validity
Reliability is not an indication of validity. In simpler terms anything that is found to be reliable is confirmed as being consistent but it surely and certainly does not measure what the researcher is intending to measure. There may be a lot of reliable tests for the measurement of specific skills for not all of them would be applicable for measuring of job performance. When we talk of accuracy and precision, reliability is a useful way for describing of precision while validity is helpful in the description of accuracy of an instrument.
Now that we know that reliability does lead or confirm validity. Surely a test that is not perfectly reliable surely cannot be perfectly valid. To clear the confusion we can say that, a reliable test may offer valid information but a test that has been proven reliable cannot be surely valid.
The fundamental point of all the theories of test reliability is that the scores of test show the influences of two types of factors:
- Factors contributing consistency: The characteristics are stable for the attribute that is being attempted to be measured
Factors contributing towards inconsistency: Those features of the individual that can have test scores but they do not have anything to do with the attribute that is getting measured.
