Recap of sampling…

Sampling example…

A survey of 300 households is being conducted to assess exposure to violence-related shocks in an urban setting in the US. To achieve the level of precision required (taking into account the finite population correction coefficient) we need to survey 100 households.

Simple random sampling

Random number table

7648 2352 6959 1937 2554 6804 9098 4316 4318 2346 7276 1880 7136 9603 0163 3152 7000 2865 8357 4475 9804 0042 1106 7949 2932 9958 9582 2235 1140 1164 7841 1688 4097 8995 5030 1785 5420 0125 4953 1332 5540 6278 1584 4392 3258 1374 1617 7427

What is the first step???

Using the random number tables below, what would be the first household sampled (by number)? How about the second, third and fourth?

Systematic sampling…

What is the sampling fraction?

Using the below random numbers table and the sampling fraction, what would be the first household sampled? How about the second, third and fourth?

Random number table

7648 2352 6959 1937 2554 6804 9098 4316 4318 2346 7276 1880 7136 9603 0163 3152 7000 2865 8357 4475 9804 0042 1106 7949 2932 9958 9582 2235 1140 1164 7841 1688 4097 8995 5030 1785 5420 0125 4953 1332 5540 6278 1584 4392 3258 1374 1617 7427

Cluster sampling…• We are doing a household survey in Zimbabwe. We

are conducting a disproportionate sample by province. Sample size calculations (taking into account a design effect of 2) indicated that we needed to sample 900 households per province. We have decided to sample 30 clusters of 30 households. The total number of households in province 1 is 150,000.

• Given that we would like to maintain a 95% confidence level and we are assuming 0.50% prevalence, what is our precision in province 1? What is our precision in province 2?

• What is our sampling fraction for province 1? • What is our first and second cluster number sampled in province 1?

no. District village number of HHs cumulativenumber of

hhs

1 Bayan-Ulgii tsagaannuur 231 231

2 Bayan-Ulgii nogoonnuur 912 1143

3 Bayan-Ulgii ulgii 3099 4242

4 Bayan-Ulgii altansogts 376 4618

5 Bayan-Ulgii bugat 484 5102

6 Bayan-Ulgii bayannuur 763 5865

7 Bayan-Ulgii tolbo 672 6537

8 Bayan-Ulgii deluun 1251 7788

9 Bayan-Ulgii bulgan 816 8604

10 Uvs bukhmoron 326 8930

11 Uvs davst 248 9178

12 Uvs ulaangom 2455 11633

13 Uvs khovd 389 12022

14 Uvs umnogobi 512 12534

15 Uvs ulgii 438 12972

16 Uvs erdeneburen 457 13429

17 khovd khovd 464 13893

18 khovd myangad 455 14348

19 khovd buyat 425 14773

20 khovd jargalant 2837 17610

21 khovd dorgon 412 18022

22 khovd chandmana 545 18567

23 khovd darvi 356 18923

etc…     etc… etc…

184 dornod matad 267 129177

Random number table

7678 2352 6959 1937 2554 6804 9098 4316 4318 2346 7276 1880 7136 9603 0163 3152 7000 2865 8357 4475 9804 0042 1106 7949 2932 9958 9582 2235 1140 1164 7841 1688 4097 8995 5030 1785 5420 0125 4953 1332 5540 6278 1584 4392 3258 1374 1617 7427