feedforward vs preview

feedforward

verb
  • To respond in advance 

noun
  • An anticipatory response to expected changes in the environment of a system 

preview

verb
  • To show or watch something, or part of it, before it is complete. 

  • To show something in advance, a facility for seeing and checking a document or photo, or changes to it, before saving and/or printing it. 

noun
  • a facility for seeing and checking a document or photo, or changes to it, before saving and/or printing it. 

  • An experience of something in advance. 

  • An advance showing of a film, exhibition etc. 

  • Something seen in advance. 

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