Behavioural Surveillance Surveys - The Wisdom of Whores

Figure 2 : Selection of Systematic Random Sample of Clusters (Brothels) PPS
Name of Measure of Cumulative Cluster Cluster Selected
Brothel Size (MOS) MOS Interval Selection Cluster
Owner
Number
1 10 10 1-10 9.98 cluster 1
2 18 28 11-28 24.75 cluster 2
3 15 43 29-43
4 16 59 44-59 48.50 cluster 3
5 12 71 60-71
6 17 88 72-88 72.25 cluster 4
7 14 102 89-102 96.00 cluster 5
8 17 119 103-119
9 10 129 120-129 119.75 cluster 6
10 13 142 130-142
11 16 158 143-158 143.50 cluster 7
12 13 171 159-171 167.25 cluster 8
13 11 182 172-182
14 14 196 183-196 191.00 cluster 9
15 11 207 197-207
16 10 217 208-217 214.75 cluster 10
17 16 233 218-233
18 15 248 234-248 238.50 cluster 11
19 15 263 249-263 262.25 cluster 12
20 13 276 264-276
21 16 292 277-292 286.00 cluster 13
22 14 306 293-306
23 17 323 307-323 309.75 cluster 14
24 20 343 324-343 333.50 cluster 15
25 17 360 344-360 357.25 cluster 16
26 15 375 361-375
27 13 388 376-388 381.00 cluster 17
28 10 398 389-398
29 15 413 399-413 404.75 cluster 18
30 16 429 414-429 428.50 cluster 19
31 17 446 430-446
32 16 462 447-462 452.25 cluster 20
33 13 475 463-475
Total 475 475
M = Cumulative MOS : a = Planned number of clusters : 20
SI = Sampling interval : M/a = 23.75 RI = Random start between = 9.98
Cluster Selection Number : 9.98, 24.75, 48.50, 72,25, etc.
B EHAV I OR A L S U R V EI L L A NC E SURV EY S APPEN DI X 3
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