Source : Webster's Revised Unabridged Dictionary (1913)

Schema \Sche"ma\, n.; pl. {Schemata}, E. {Schemas}. [G. See
   {Scheme}.] (Kantian Philos.)
   An outline or image universally applicable to a general
   conception, under which it is likely to be presented to the
   mind; as, five dots in a line are a schema of the number
   five; a preceding and succeeding event are a schema of cause
   and effect.

Source : WordNet®

schema
     n 1: an internal representation of the world; an organization of
          concepts and actions that can be revised by new
          information about the world [syn: {scheme}]
     2: a schematic or preliminary plan [syn: {outline}, {scheme}]
     [also: {schemata} (pl)]