Even numbered scales force respondent to lean one way or the other, but may distort the information when respondents have a genuinely neutral view. Odd numbered scales (i.e., 1-5 or 1-7) allow the respondent to select a neutral position, but may distort the data when respondents are leaning in one direction or the other, but select the neutral position because it feels safe, or is easiest.
There is no perfect solution in choosing odd or even numbered scales. The real issue is how you get the most useful information for your purpose.
The question is do you want to force the person to make a choice, or let them be neutral. |