This study examined the effect of the position of answer category “neither” of a rating scale (applicable/not applicable) of a self-administered questionnaire on the subjects' response rate, ease of answering, and misunderstanding of answer options in the case of a web survey. An eye tracking experiment was conducted on 56 university students. Fifty responses were analyzed and 6 were excluded due to insufficient data. The results showed that: (1) when “neither”is placed at the far right of the rating scale, the response rate is lower than when at the center; (2) when “neither” is placed at the far right, some participants mistakenly thought it displayed the most negative answer of “not applicable” because they did not observe the right side carefully; and (3) participants who correctly recognized the position of “neither” on the right had a higher fixation counts on the answer options and larger eye movements than those who did not recognize it.
