Null hypothesis: This new experimental drug is no more effective at preventing malaria than a placebo.
Alternative hypothesis: This new experimental drug can help to prevent malaria-The data: One group is randomly chosen to receive the new experi¬mental drug, and a control group receives a placebo. At the end of some period of time, the group receiving the experimental drug has far fewer cases of mal ari a than the control group. This would be an extremely unlikely utcome if the experimental drug had no medical impact. As a result, we reject the null hypothesis that the new drug has no impact (beyond that of placebo), and we accept the logical alternative, which is our alternative ypothesis: This new experimental drug can help to prevent malaria.