1. Acupuncture - Involves the act of needle insertion, although there are many other non-invasive techniques for acupuncture point stimulation. Points may be selected according to:

• traditional medical systems;
• symptoms;
• point selection based on the scientific relationships of point function; and
• point prescription.

2. Real acupuncture - Acupuncture given as a real clinical treatment.

3. Sham acupuncture - Inappropriate acupuncture for the condition being treated taking into account the acupuncture microsystem.

4. Mock Transcutaneous Electrical Nerve Stimulation - Treatment with a defunctioned TENS machine in which no electrical stimulus reaches the patient but the TENS machine appears to be active.

5. Minimal acupuncture - Shallow needle insertion which in some studies has been used as a placebo, but in others as real treatment.

6. Control group - A comparative group with which to compare the effects of real acupuncture treatment. The control group might be untreated or receive conventional medical treatment.

7. Placebo - If acupuncture is defined as skin penetration with an acupuncture needle, then true placebo acupuncture would appear to be impossible. Less effective forms of acupuncture can be perfectly adequate controls, and in some specific instances it may be possible to mimic acupuncture in a credible manner.