The book appears to be alright. But I can not find any evidence of how this system was researched and tested. I am therefore still a bit suspicious.

Hi all, My question is, how did Denise Eide develop, research and test her rule based spelling system? I have read the book and find it very interesting. But before I want to teach it to my children, I want to understand where this system came from. I want to understand how Denise developed and found a correlation between her rules, the phonograms, and all English words. Also, to proof, such a system requires a reasonable high level of mathematics. If somebody could explain it to me I would feel much more confident in teaching the logic of English myself.