in effect vs materially

in effect

adv
  • For all practical purposes; in practice; actually; essentially; basically. 

adj
  • Operating or functioning; in force; in play. 

materially

adv
  • To a significant degree. 

  • In a material manner; with regard to physical things or characteristics. 

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