corroboration vs documentation

corroboration

noun
  • That which corroborates. 

  • The act of corroborating, strengthening, or confirming; addition of strength; confirmation 

documentation

noun
  • Documentary evidence and sources. 

  • Documents that explain the operation of a particular machine or software program. 

  • Something transposed from a thought to a document; the written account of an idea. 

  • Comments that explain the usage of individual functions, libraries and blocks of code. 

  • A documentary. 

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