methodical vs methodological

methodical

adj
  • In an organized manner; proceeding with regard to method; systematic. 

  • Arranged with regard to method; disposed in a suitable manner, or in a manner to illustrate a subject, or to facilitate practical observation. 

methodological

adj
  • Of, pertaining to, or using methodology or a methodology. 

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