Use the scan method to test for clusters of a specified duration (the scanning window). This method will detect both single and multiple clusters, but is most sensitive when the clusters `fit' in the scanning window.
Use Larsen's method to test for a clustering of cases about a single point in time. Larsen's test is not sensitive to multiple clusters. The data must be rare so that some of the time periods have 0 cases.
Use Dat's method to test for a clustering of cases such that one or more of the time cells has an excess of cases. Dat's test can only be used when there are 5 to 10 time intervals.