extrapolation vs guesswork

extrapolation

noun
  • An inference about some hypothetical situation based on known facts. 

  • A calculation of an estimate of the value of some function outside the range of known values. 

  • The diametric opposite of interpolation. 

guesswork

noun
  • An estimate, judgment or opinion made by guessing, from limited information. 

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