reliability vs uncertainty

reliability

noun
  • The quality of being reliable, dependable, or trustworthy. 

  • the ability to measure the same thing consistently (of a measurement indicating the degree to which the measure is consistent); that is, repeated measurements would give the same result (See also validity). 

  • measurable time of work before failure 

uncertainty

noun
  • Doubt; the condition of being uncertain or without conviction. 

  • A parameter that measures the dispersion of a range of measured values. 

  • Something uncertain or ambiguous. 

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