authoritative vs normative

authoritative

adj
  • Highly accurate or definitive; treated or worthy of treatment as a scholarly authority 

  • Having a commanding style. 

  • Arising or originating from a figure of authority 

normative

adj
  • Of or pertaining to a norm or standard. 

  • Conforming to a norm or norms. 

  • Attempting to establish or prescribe a norm. 

noun
  • A regulation imposed to preserve a norm. 

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