Research participants don’t always do what they are supposed to do. When their personal interests conflict with the demands of study participation, some participants surreptitiously break the rules. Rule-breaking participants don’t normally intend to compromise the study process; they simply see their own interests as more important than study rules aimed at generating good data.
Some participants have written about their rule-breaking and others have disclosed it to reporters and scholars writing about human trials. Researchers also report discovering various forms of rule-breaking that participants tried to hide. But because not many studies use techniques that can uncover rule-breaking, much of the behavior isn’t detected.