Remember not to respond right in the center/don't care/Don'y know. Choose one way or the other slighly.
We were told that total number of answers to each question varied because center responses were discarded.
WRONG! Responses in the "middle" are just as valid as any other response.
I had a center manager who told me to avoid the "center" selection. (In other words, she was hinting me to hit the "top" choice instead.) This assumes that "Don't Know" has a value of zero. The scale most likely runs from 1-5. So... if you don't think "Strongly Agree", "Agree", "Disagree", or "Strongly Disagree" match your feelings, you SHOULD go with the center. I don't know why they call it "Don't Know." That almost makes you feel like you're stupid. It would more accurate if it said "Neither Agree or Disagree". That way you wouldn't have to "lie". (I take a lot of marketing surveys online, so I'm used to seeing a 1-5 scale setup that way.)
BTW, I had to laugh, because when I was took the ERI with that particular manager I was in a statistics class, and, even if the middle option did equal a zero value, zero is still statistically significant! It's not like that response gets ignored!