Russel-Research-Method-in-Anthropology

122 Chapter 5
behavior. However, don’t let that bother you. Go ahead and shoot your free
throws. (Leith 1988:61)
What a wonderfully simple, utterly diabolic experiment. You can guess the
result: There was a significantly greater probability of choking if you were
among the groups that got that little pep talk, irrespective of whether they’d
been given the warm-up pretest.
The Two-Group Pretest-Posttest without Random Assignment
Figure 5.1c shows the design for a quasi-experiment—an experiment in
which participants are not assigned randomly to the control and the experi-
Time 1 Time 2
Assignment Pretest
Intervention Posttest
Group 1 O X O
1 2
Group 2 O O
Figure 5.1c. The classic design without randomization: The quasi-experiment.
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mental condition. This compromise with design purity is often the best we can
do.
Program evaluation research is usually quasi-experimental. Consider a program
in rural Kenya in which women farmers are offered instruction on applying
for bank credit to buy fertilizer. The idea is to increase corn production.
You select two villages in the district—one that gets the program, and one
that doesn’t. Before the program starts, you measure the amount of credit, on
average, that women in each village have applied for in the past 12 months. A
year later, you measure again and find that, on average, women in the program
village have applied for more agricultural credit than have their counterparts
in the control village.
Campbell and Boruch (1975) show how this research design leads to problems.
But suppose that the women in the program village have, on average,
more land than the women in the control village have. Would you (or the
agency you’re working for) be willing to bet, say, $300,000 on implementing
the program across the district, in, say, 30 villages? Would you bet that it was
the intervention and not some confound, like the difference in land holdings,
that caused the difference in outcome between the two villages?
The way around this is to assign each woman randomly to one of the two
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