Efectiveness or Effectiveness: How To spell?
The word Efectiveness is misspelled against Effectiveness, a noun meaning "The quality of being effective."
Effectiveness has double "ff" is mispronounced as "f"Remember double 'FF' in between the strings E & ectiveness which should not be misspelled with single 'F'
Wrong Spelling:  E-f-ectiveness  Correct Spelling:  E-ff-ectiveness 
Find more wrongly spelled words of Effectiveness to spell it well.