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<p> Suppose one wanted to investigate the <a href="page.php?w=abortion_-_breast_cancer_hypothesis">abortion - breast cancer hypothesis</a>, which postulates a causal link between induced abortion and the incidence of breast cancer.  In a hypothetical controlled experiment, one would start with a large subject pool of pregnant women and divide them randomly into a treatment group (receiving induced abortions) and a control group (not receiving abortions), and then conduct regular cancer screenings for women from both groups.  Such an experiment would</p><p>
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