Heterogeneous versus core clusters. Clusters A and C are the heterogeneous clusters reported by SaTScan with a large maximum-size. Cluster B, D, E are identified as core clusters by the proposed reliability visualization. The clusters' properties are listed in Table 1. The clusters above are manually circled and labelled for illustration purposes. Other irrelevant clusters (e.g., a single-county cluster near the Great Lakes) are not circled and labelled.