Table 3 Illustrative example to determine the number of clusters (k) for a fixed cluster size (m) and set maximum likely error (10%) across range of intra-cluster correlation coefficients (ICCs)
Number of clusters (k) needed by cluster size (m) and ICC | |||||
|---|---|---|---|---|---|
m = 10 | m = 20 | m = 50 | m = 75 | m = 100 | |
0.30 | 38 | 35 | 33 | 33 | 32 |
0.15 | 26 | 21 | 19 | 18 | 18 |
0.10 | 21 | 17 | 14 | 14 | 13 |
0.05 | 17 | 12 | 10 | 9 | 9 |