Definition of Control (research)
Control (research): In research, control subjects or control procedures permit comparison with experimental results. The first controlled clinical research was probably done in 1875 by the British naval surgeon James Lind who, on board the HMS Salisbury, gave sailors with scurvy either oranges or lemons or cider or vinegar or nutmeg (or another treatment) and after just six days discovered that the citrus-consuming sailors had recovered from scurvy, until then the scourge of extended sea voyages, while the sailors who had been given the other treatments remained uncured.