datum vs variance

datum

noun
  • A fact known from direct observation. 

  • A premise from which conclusions are drawn. 

  • A floating reference point, or SLDMB, used to evaluate surface currents in a body of water. Often employed by coastal search and rescue. 

  • A fixed reference point or set of reference points which precisely define a system of measurement or a coordinate system. 

verb
  • To provide missing data points by using a mathematical model to extrapolate values that are outside the range of a measuring device. 

variance

noun
  • A difference between what is expected and what is observed; deviation. 

  • A discrepancy between two legal documents. 

  • A departure from a cause of action originally in a complaint. 

  • An official permit to do something that is ordinarily forbidden by regulations. 

  • The act of varying or the state of being variable. 

  • The state of differing or being in conflict. 

  • The number of degrees of freedom in a system. 

  • Covariance and contravariance generally. 

  • The second central moment in probability. 

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