doctoral thesis vs position paper

doctoral thesis

noun
  • A research paper that a student writes in order to complete the requirements for a doctorate; a dissertation. 

position paper

noun
  • An essay or report which expresses a position, conclusion, or recommendation concerning a contested issue or undecided question and which usually contains arguments or reasons in support of this position. 

How often have the words doctoral thesis and position paper occurred in a corpus of books? (source: Google Ngram Viewer )