control group
Control Con*trol", n. [F. contr[^o]le a counter register, contr. fr. contr-r[^o]le; contre (L. contra) + r[^o]le roll, catalogue. See {Counter} and {Roll}, and cf. {Counterroll}.] 1. A duplicate book, register, or account, kept to correct or check another account or register; a counter register. [Obs.] --Johnson. [1913 Webster]

2. That which serves to check, restrain, or hinder; restraint. ``Speak without control.'' --Dryden. [1913 Webster]

3. Power or authority to check or restrain; restraining or regulating influence; superintendence; government; as, children should be under parental control. [1913 Webster]

The House of Commons should exercise a control over all the departments of the executive administration. --Macaulay. [1913 Webster]

4. (Mach.) The complete apparatus used to control a mechanism or machine in operation, as a flying machine in flight; specifically (A["e]ronautics), the mechanism controlling the rudders and ailerons. [Webster 1913 Suppl.]

5. (Climatology) Any of the physical factors determining the climate of any particular place, as latitude,distribution of land and water, altitude, exposure, prevailing winds, permanent high- or low-barometric-pressure areas, ocean currents, mountain barriers, soil, and vegetation. [Webster 1913 Suppl.]

6. (Technology) in research, an object or subject used in an experimental procedure, which is treated identically to the primary subject of the experiment, except for the omission of the specific treatment or conditions whose effect is being investigated. If the control is a group of living organisms, as is common in medical research, it is called the

{control group}.

Note: For most experimental procedures, the results are not considered valid and reliable unless a proper control experiment is performed. There are various types of control used in experimental science, and often several groups of subjects serve as controls, being subjected to different variations of the experimental procedure, or controlling for several variables being tested. When the effects caused by an experimental treatment are not consistent and obvious, statistical analysis of the results is typically used to determine if there are any significant differences between the effects of different experimental conditions. [PJC]

7. (Technology) the part of an experimental procedure in which the controls[6] are subjected to the experimental conditions. [PJC]

8. the group of technical specialists exercising control by remote communications over a distant operation, such as a space flight; as, the American Mission Control for manned flights is located in Houston. [PJC]

{Board of control}. See under {Board}. [1913 Webster]


The Collaborative International Dictionary of English. 2000.

Look at other dictionaries:

  • control group — conˈtrol group noun [countable] STATISTICS in a test, a group of people or things that you do not test and that you then compare with the group being tested. By using a control group, you can see if the results of your test are caused by the… …   Financial and business terms

  • control group — n. a group that serves as the control in a scientific experiment; specif., such a group that does not receive the substance, drug, treatment, etc. being tested …   English World dictionary

  • control group — A group used for comparison with another, either because it represents the most common or typical case, or because it illustrates the absence of some phenomenon being studied. Human beings are not inert, lifeless matter, and hence cannot be… …   Dictionary of sociology

  • control group — (in an experiment or clinical trial) a group of subjects closely resembling the treatment group in many demographic variables but not receiving the active medication or factor under study and thereby serving as a comparison group when treatment… …   Useful english dictionary

  • control group — With reference to those whose communications with an attorney on behalf of a corporation are within the attorney client privilege, this group consists of those persons who have authority to control, or substantially participate in, decisions… …   Black's law dictionary

  • control group — With reference to those whose communications with an attorney on behalf of a corporation are within the attorney client privilege, this group consists of those persons who have authority to control, or substantially participate in, decisions… …   Black's law dictionary

  • control group — /kənˈtroʊl grup/ (say kuhn trohl groohp) noun a group which acts as a control (def. 6) in an experiment where the results are analysed statistically, as in the testing of drugs …   Australian English dictionary

  • control group — (in an experiment or clinical trial) a group of subjects closely resembling the treatment group in many demographic variables but not receiving the active medication or factor under study and thereby serving as a comparison group when treatment… …   Universalium

  • control group — In a clinical trial, the group that does not receive the new treatment being studied. This group is compared to the group that receives the new treatment, to see if the new treatment works …   English dictionary of cancer terms

  • control group — experimental group used to verify the results of an experiment via comparison to the subject group …   English contemporary dictionary

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