← Back to QUESTIONSTAR
Chapter 2 · Survey: Measurement and Scaling · Slide 60/274

Even or Odd Number of Scale Categories

The middle option attracts many undecided respondents — and those who are reluctant to reveal their opinion.

2.3 · Constructing Rating Scales Design Question 3

Even or Odd Number of Scale Categories

3
Even vs. Odd Number
If a neutral or indifferent response is a viable option for some respondents, an odd number of categories should be chosen.

Odd number — with a midpoint

Strongly disagree
Disagree
Neutral
Agree
Strongly agree
Allows a neutral response

Even number — without a midpoint

Strongly disagree
Disagree
Agree
Strongly agree
Forces a leaning

The middle option attracts many undecided respondents — and those who are reluctant to reveal their opinion.

This can bias the measures of central tendency and variance.

Do we want or need “contrast” on controversial attitudes?

QUESTIONSTAR · Dr. Paul Marx 60 / 274
To the full presentation