This document discusses measurement system analysis for attribute data. It explains that attribute or ordinal measurement systems use accept/reject criteria or ratings to determine quality levels. The Kappa and Kendall techniques can be used to evaluate attribute and ordinal measurement systems, respectively. These methods assess consistency between raters when classifying units. Having clear operational definitions is important for attribute measurements, as poor agreement between raters usually stems from unclear definitions. Failing to evaluate attribute measurement systems before using the data can lead to making flawed decisions if the system is inconsistent.