Estimating Ordinal Reliability Using SAS

In evaluation instruments and tests individual items are often collected using an ordinal measurement or likert type scale. Typically measures such as Cronbach’s alpha are estimated using the standard Pearson correlation. Gadderman, Guhn and Zumbo (2012) illustrate how using the standard Pearson correlations may yield biased estimates of reliability when the data are ordinal and present methodology for using the polychoric correlation in reliability estimates as an alternative. This session shows how to implement the methods of Gadderman, Guhn and Zumbo using SAS ® software. An example, will be presented that incorporates these methods in the estimation of the reliability of an active learning post-occupancy evaluation instrument developed by Steelcase Education Solutions researchers.