Comparison of areas of clustering and dispersion between the Getis-Ord General G and Moran’s I statistics.

<p>Getis-Ord quadrats (on left) display areas where the General G value was significant for clustering. Moran’s I quadrats (on right) display areas of significantly high clustering and significantly low clustering. These statistics recognize slightly different areas as “clustered” due to differences in the ways in which they calculate spatial relationships. Also note that between sampling times, significant clusters often overlap or are immediately adjacent to one another, suggesting that transmission occurs over a relatively small scale.