An interesting find in one of my trade magazines: The coefficient of variation (CV), sometimes called the relative standard deviation, is often used to assess the quality of an assay,1 the diversity in organizations2 or as a benchmark for ranking.3 It is measured as a fraction or percentage of how much variation exists in a variable in relation to the mean, so it represents a highly useful-and easy to interpret-concept in data analysis. http://www.asq.org/quality-progress/2009/07/statistics-roundtable/player-rankings.html