Ineffectivenes or Ineffectiveness: How To spell?
The word Ineffectivenes is misspelled against Ineffectiveness, a noun meaning "Quality of being ineffective."
Ineffectiveness has double 'ss' in the end mispronounced as 's'Remember double 'SS' appears in the end of this word which should not be misspelled with single 'S'
Wrong Spelling:  ineffectivene-s  Correct Spelling:  ineffectivene-ss 
Find more wrongly spelled words of Ineffectiveness to spell it well.