expectation vs theory

expectation

noun
  • The act or state of expecting or looking forward to an event as about to happen. 

  • The value of any chance (as the prospect of prize or property) which depends upon some contingent event. 

  • The first moment; the long-run average value of a variable over many independent repetitions of an experiment. 

  • The arithmetic mean. 

  • The leaving of a disease principally to the efforts of nature to effect a cure. 

  • The prospect of the future; grounds upon which something excellent is expected to occur; prospect of anything good to come, especially of property or rank. 

  • That which is expected or looked for. 

theory

noun
  • A description of an event or system that is considered to be accurate. 

  • A coherent statement or set of ideas that explains observed facts or phenomena and correctly predicts new facts or phenomena not previously observed, or which sets out the laws and principles of something known or observed; a hypothesis confirmed by observation, experiment etc. 

  • A field of study attempting to exhaustively describe a particular class of constructs. 

  • A set of axioms together with all statements derivable from them; or, a set of statements which are deductively closed. Equivalently, a formal language plus a set of axioms (from which can then be derived theorems). The statements may be required to all be bound (i.e., to have no free variables). 

  • A hypothesis or conjecture. 

  • The underlying principles or methods of a given technical skill, art etc., as opposed to its practice. 

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