ladder vs stratification

ladder

noun
  • The hierarchy or ranking system within an organization, such as the corporate ladder. 

  • A length of unravelled fabric in a knitted garment, especially in nylon stockings; a run. 

  • A frame, usually portable, of wood, metal, or rope, used for ascent and descent, consisting of two side pieces to which are fastened rungs (cross strips or rounds acting as steps). 

  • A series of stages by which one progresses to a better position. 

  • In the game of go, a sequence of moves following a zigzag pattern and ultimately leading to the capture of the attacked stones. 

verb
  • Of a knitted garment: to develop a ladder as a result of a broken thread. 

  • To ascend (a building, a wall, etc.) using a ladder. 

  • To arrange or form into a shape of a ladder. 

  • To close in on a target with successive salvos, increasing or decreasing the shot range as necessary. 

stratification

noun
  • society's categorization of people into socioeconomic strata 

  • the vertical layering of vegetation in a forest 

  • process of treating seeds to simulate natural conditions that the seeds must experience before germination can occur; most often the process involves exposure to cold in which case it may also be called cold treatment 

  • the process leading to the formation or deposition of layers, especially of sedimentary rocks 

  • a layering of musical texture 

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