Suggestion 5: Ask yourself if there was a control group. The key importance of a control group in any experiment is frequently over-looked by the unsophisticated—an error to which you are no longer susceptible. The popular media are full of reports of “experiments” performed without control groups: “Talking to Plants Speeds Growth,” “Special Diet Controls Hyperactivity in Children,” “Graduates of Firewalking Seminar Risk Their Soles.”