Purpose: Graduate admission has become a critical process for quality assurance in tertiary education. Hitherto, most research has investigated the validity of admissions instruments. However, surprisingly little work has been conducted on the overall organization of admission, which often remains "informal, ad hoc, and lacking in…

The nature of percentile ranks scores is explored using concrete heuristic examples. It is explained why arithmetic operations require measurement on equal-interval scales, and that percentile ranks are not measured on equal-interval scales and therefore may not be added or averaged. The consequences of inappropriately adding percentile ranks are…