black box vs formation

black box

noun
  • A theoretical construct or device with known input and output characteristics but unknown method of operation. 

  • A flight recorder; the brightly colored cockpit voice recorders and flight data recorders in an aircraft designed to aid in determining the cause of an accident. 

  • A device used in phreaking that prevents the calling party from being billed for the call placed. 

  • A type of theater characterized by a lack of decoration or complex mechanisms. 

  • Any similar device on motor vehicles, such as rail event recorders and ship trip recorders. 

verb
  • To focus on the inputs and outputs without worrying about the internal complexity. 

formation

noun
  • Something possessing structure or form. 

  • An arrangement of players designed to facilitate certain plays. 

  • An arrangement of moving troops, ships, or aircraft, such as a wedge, line abreast, or echelon. Often "in formation". 

  • A structure made of two categories, two functors from the first to the second category, and a transformation from one of the functors to the other. 

  • The act of assembling a group or structure. 

  • The process during which something comes into being and gains its characteristics. 

  • A layer of rock of common origin. 

  • A grouping of military units or smaller formations under a command, such as a brigade, division, wing, etc. 

  • The process of influencing or guiding a person to a deeper understanding of a particular vocation. 

How often have the words black box and formation occurred in a corpus of books? (source: Google Ngram Viewer )