The Ederer-Myers-Mantel method (Ederer, Myers, and Mantel 1964) tests for temporal clustering in several time series simultaneously (group level data). Case counts in consecutive time periods for several areas are required. Therefore, the method is biased by changes in population size through time. The test is insensitive to different population sizes over the areas. The number of time intervals in the series must be between 2 and 5.
