notice vs observe

notice

verb
  • To become aware of; to observe. 

  • To be noticeable; to show. 

noun
  • A published critical review of a play or the like. 

  • A written or printed announcement. 

  • Advance notification of termination of employment, given by an employer to an employee or vice versa. 

  • The act of observing; perception. 

  • A formal notification or warning. 

  • Prior notification. 

observe

verb
  • To notice or view, especially carefully or with attention to detail. 

  • To take note of and celebrate (a holiday or similar occurrence); to follow (a type of time or calendar reckoning). 

  • To comment on something; to make an observation. 

  • To follow or obey the custom, practice, or rules (especially of a religion). 

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