Assertion: placebo | /r/ObjectUse | used as control
Facets:
value: in the experiment
type: LOCATION
Source sentences:
text: Maybe a placebo is just an inert substance used as a control, which just happens to exert a placebo effect.
text: Even in carefully controlled clinical trials where placebos have been used as the control in the experiment, some patients improve simply because they think they are getting the real medicine.