Although participants could not practically be blinded to the kind of tape they received, they were blinded to the hypothesis of the study. Randomization was blinded to the observer (wart size assessor) by having the subjects remove the tape or clavi ring prior to each assessment. The CONSORT statement6 recommends reporting the method used to assess blinding; however, this is often not done.7 To their credit, de Haen and colleagues assessed blinding in this study using 2 methods. First, the investigators asked how well the parents of participants (subject proxies) expected the treatment to work. The assumption is that those who believe they are in the experimental group will have higher expectations of treatment success. In this study, parents in both groups had similar expectations. Second, the investigators asked the observer whether she knew which kind of tape the subjects received. The observer reported that she knew the assigned group in 31% of the duct tape group compared with 17% of the placebo group, a statistically significant difference. Although the observer was incorrect about assignment more than half of the time overall, the presence of incomplete, asymmetric blinding of the observer would theoretically bias the results toward finding that duct tape was more effective. The investigators did mention that the observer was aware of the study hypothesis. Even if she were blinded to the study hypothesis, the observer could still have subconsciously formed hypotheses of her own, which could potentially bias the results.