hypothesis vs notion

hypothesis

noun
  • The antecedent of a conditional statement. 

  • An assumption taken to be true for the purpose of argument or investigation. 

  • Used loosely, a tentative conjecture explaining an observation, phenomenon or scientific problem that can be tested by further observation, investigation and/or experimentation. As a scientific term of art, see the attached quotation. Compare to theory, and quotation given there. 

notion

noun
  • Inclination; intention; disposition. 

  • Mental apprehension of whatever may be known, thought, or imagined; idea, concept. 

  • A sentiment; an opinion. 

  • An invention; an ingenious device; a knickknack. 

  • Any small article used in sewing and haberdashery, either for attachment to garments or as a tool, such as a button, zipper, or thimble. 

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