extract vs involve

extract

verb
  • To select parts of a whole 

  • To determine (a root of a number). 

  • To take by selection; to choose out; to cite or quote, as a passage from a book. 

  • To draw out; to pull out; to remove forcibly from a fixed position, as by traction or suction, etc. 

  • To withdraw by expression, distillation, or other mechanical or chemical process. Compare abstract (transitive verb). 

noun
  • A decoction, solution, or infusion made by drawing out from any substance that which gives it its essential and characteristic virtue 

  • Something that is extracted or drawn out. 

  • Ancestry; descent. 

  • A draft or copy of writing; a certified copy of the proceedings in an action and the judgment therein, with an order for execution. 

  • Any substance extracted is such a way, and characteristic of that from which it is obtained 

  • A solid preparation obtained by evaporating a solution of a drug, etc., or the fresh juice of a plant (distinguished from an abstract). 

  • A portion of a book or document, incorporated distinctly in another work; a citation; a quotation. 

involve

verb
  • To comprise or include; to have as a related part. 

  • To take in; to gather in; to mingle, blend or merge. 

  • To cause or engage (someone or something) to participate or to become connected or implicated. 

  • To complicate or make intricate. 

  • To envelop, enfold, entangle. 

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