The DICT Development Group

Search for:
Search type:

Database copyright information
Server information

1 definition found
 for control group
From The Collaborative International Dictionary of English v.0.48 :

  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.
        [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.
     7. (Technology) the part of an experimental procedure in
        which the controls[6] are subjected to the experimental
     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.
     Board of control. See under Board.
        [1913 Webster]

Contact=webmaster@dict.org Specification=RFC 2229