assessment vs trial run

assessment

noun
  • An appraisal or evaluation. 

  • The act of assessing or an amount (of tax, levy or duty etc) assessed. 

trial run

noun
  • An empirical test of the suitability or effectiveness of a method or thing by running it at least once. 

  • An empirical test of the suitability or capability of a person or actor by letting him perform at least once. 

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