bird's-eye view vs ken

bird's-eye view

noun
  • The view from directly or high above. 

  • A general overview or summary of a topic. 

ken

noun
  • Range of sight. 

  • Youth or children's group. 

  • A Japanese unit of length equal to six shakus 

  • Knowledge, perception, or sight. 

  • The tsurugi 

verb
  • To know, perceive or understand. 

How often have the words bird's-eye view and ken occurred in a corpus of books? (source: Google Ngram Viewer )