datum vs opinion

datum

noun
  • 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. 

  • A fact known from direct observation. 

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

opinion

noun
  • The judgment or sentiment which the mind forms of persons or things; estimation. 

  • A belief, judgment or perspective that a person has formed, either through objective or subjective reasoning, about a topic, issue, person or thing. 

  • a judicial opinion delivered by an Advocate General to the European Court of Justice where he or she proposes a legal solution to the cases for which the court is responsible 

  • The formal decision, or expression of views, of a judge, an umpire, a doctor, or other party officially called upon to consider and decide upon a matter or point submitted. 

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