&gt; consider it an ethics violation to use a control group, the logic being that in denying your experimental method to the control group you&#x27;re putting them at a disadvantage.<p>Oh man. Someone should tell them about double-blind clinical trials for  cancer treatment. (Those can be, and sometimes are, &quot;stopped for efficiency&quot;, when a midway evaluation shows the treatment is so effective that they already have a statistically significant result. They then start giving the treatment to both groups, I believe.)