A restricted language may be used in a language-based interaction in order to make natural language processing easer or more reliable. This might mean that user can only use grammatical forms or words from a fixed set, often through drop-down menus. Even where a restricted language is not imposed by the system, users may modify their own language in order to match terms that are easily understood. Often this modification is unconscious.
Used in Chap. 13: page 201