Wait a moment. I can agree that it’s a “common sense” guess that
P(bad spelling | less education) >> P(bad spelling)
but what that “technique” would imply is:
P(finds text with bad spelling belivable | less education) >> P(finds text with bad spelling belivable)
...which is kinda more interesting. So to speak.
Just mentioning, but It’s a good policy to avoid feeling good about figuring out anwers you already knew. ---> http://lesswrong.com/lw/il/hindsight_bias/