Types of Reliability

You learned in the Theory of Reliability that it's not possible to calculate reliability exactly. Instead, we have to estimate reliability, and this is always an imperfect endeavor. Here, I want to introduce the major reliability estimators and talk about their strengths and weaknesses. There are four general classes of reliability estimates , each of which estimates reliability in a different way. They are: Inter-Rater or Inter-Observer Reliability Used to assess the degree to which different raters/observers give consistent estimates of the same phenomenon. Test-Retest Reliability Used to assess the consistency of a measure from one time to another. Parallel-Forms Reliability Used to assess the consistency of the results of two tests constructed in the same way from the same content domain. Internal Consistency Reliability Used to assess the consistency of results across items within a test. Let's discuss each of these in turn. Inter-Rater or Inter-Observer Reliability Whene...