Russel-Research-Method-in-Anthropology

160 Chapter 6
of many small blocks in a population and can calculate their respective proportionate
contributions to the total population.
PPS Samples in the Field
What do you do when you don’t have neat clusters and neat sampling
frames printed out on a computer by a reliable government agency? The
answer is to place your trust in randomness and create maximally heterogeneous
clusters from which to take a random sample.
Draw or get a map of the area you are studying. Place 100 numbered dots
around the edge of the map. Try to space the numbers equidistant from one
another, but don’t worry if they are not. Select a pair of numbers at random
and draw a line between them. Now select another pair of numbers (replace the
first pair before selecting the second) and draw a line between them. In the
unlikely event that you choose the same pair twice, simply choose a third pair.
Keep doing this, replacing the numbers each time. After you’ve drawn 20–50
lines across the map (depending on the size of the map), you can begin sampling.
Notice that the lines drawn across the map (see figure 6.1) create a lot of
wildly uneven spaces. Since you don’t know the distribution of population
density in the area you are studying, this technique maximizes the chance that
TO MOUNTAINS
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CHURCH OF
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Figure 6.1. Creating maximally heterogeneous sampling clusters in the field.