A drug for female sexual dysfunction called Intrinsa was tested in 2004, both for efficacy and for possible dangerous side effects before being considered for approval by the Food and Drug Administration. A report of clinical trials states: "Fifty-two percent of those [women] given the drug said they experienced a ‘meaningful benefit' in their sex-lives-but so did 31% of those who were given the placebo."7 Who controlled the values of the explanatory variable in this study: the women or the researchers?