pop quiz vs scrutiny

pop quiz

noun
  • A quiz or test given without warning or prior announcement. 

scrutiny

noun
  • An examination by a committee of the votes given at an election, for the purpose of correcting the poll. 

  • Intense study of someone or something. 

  • Thorough inspection of a situation or a case. 

  • A ticket, or little paper billet, on which a vote is written. 

  • An examination of catechumens, in the last week of Lent, who were to receive baptism on Easter Day. 

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