Sampling for Region-Aggregated Spatial Scan Statistics
This study addresses the mismatch between areal-aggregated geographic data and point-based spatial scan statistics, where representing regions by their centroids discards critical spatial information and reduces statistical power. To mitigate this limitation, the authors propose a simple yet scalable preprocessing strategy: uniformly sampling 20–50 points within each region’s geometry and distributing the region’s observed count equally among these points. This approach better preserves the underlying spatial distribution while remaining computationally tractable. Empirical evaluations demonstrate that the method substantially enhances the detection performance of spatial scan statistics on aggregated regional data across diverse scenarios. The authors advocate its adoption as a standard preprocessing step for analyzing areal-aggregated datasets in spatial anomaly detection tasks.