noun, plural: controls
(1) Influence or authority over.
(2) That which purposefully direct, manipulate, manage, regulate, restrain, or cause change.
To take charge of; to influence or direct over; to restrain, prevent, or manipulate.
In scientific experiments, the use of controls allows to study one variable or factor at a time. It is, however, important that both the control and other (experimental) group(s) are exposed to the same conditions apart from the one variable under study. Doing so will help draw conclusions that are more accurate and reliable.
Word origin: Middle English controllen, borrowed from Middle French contreroller, 'check against a duplicate account', from Medieval Latin contrarotulare, from contra 'opposite' + rotula 'roll, little wheel'.
Related forms: controllable (adjective), controlling (verb: present participle), controlled (verb: simple past).