Additional Metric for Communicating Group Performance Differences

摘要

The common practice of expressing group performance differences in standarddeviation units conveys useful but limited information. Reporting the percentage of the time a member from a lower performing group is expected to outperform a member from a higher performing group would enhance understanding of the magnitude of the difference. Furthermore, the proposed percentage metric is able to easily deal with group variability differences in addition to mean group differences. An analytical approach was used to convert group performance differences from standard deviation units to the proposed metric. The slope of the relationship between the two metrics is nearly linear through a one standard deviation group performance difference. Tables are presented that can be used to convert group performance differences in standard deviation units to the new metric.