Sample Size Determination in Test-Retest and Cronbach Alpha Reliability Estimates

The estimation of reliability in any research is a very important thing. For us to achieve the goal of the research, we are usually faced with the issue of when the measurements are repeated, are we sure we will get the same result? Reliability is the extent to which an experiment, test, or any measuring procedure yields the same result on repeated trials. If a measure is perfectly reliable, there is no error in measurement, that is, everything we observe is the true score. However, it is the amount/degree of error that indicates how reliable, a measurement is. The issue of sample size determination has been a major problem for researchers and psychometricians in reliability studies. Existing approaches to…