conciliation vs placation

conciliation

noun
  • The process of bringing peace and harmony; the ending of strife. 

  • A form of alternative dispute resolution, similar to but less formal than mediation, in which the parties bring their dispute to a neutral third party, who helps lower tensions, improve communications and explore possible solutions. 

placation

noun
  • A process or act of placating; appeasement or an expression of appeasement. 

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