"Effect. As noun, means result; as verb, means to bring about, accomplish (not to be confused with affect, which means "to influence")."
http://www.bartleby.com/141/strunk3.html
Sorry, derleth. It's not a matter of someone defining correct usage. It's simply a matter of looking at the dictionary definitions of the words 'affect' and 'effect'. Affect simply means to influence while effect means to bring about.
"Effect. As noun, means result; as verb, means to bring about, accomplish (not to be confused with affect, which means "to influence")." http://www.bartleby.com/141/strunk3.html
Affect vs. Effect: http://www.dartmouth.edu/~sullivan/CommonWritingErrors.html#...