Here is one of the common scales that we see in questionnaires. It is used to measure many things. In this example, I will show it used to measure health:
Q: Would you say your health is:
__ Excellent
__ Very good
__ Good
__ Fair
__ Poor
This is an unbalanced bipolar scale. There are three levels of good (excellent, very good, and good) with fair being the midpoint and one level of bad (poor). Unbalanced scales like this result in biased responses.
To avoid the bias, add the corresponding levels for the negative side of the scale. With fair as the midpoint, we would have something like this:
Q: Would you say your health is:
__ Very good
__ Good
__ Somewhat good
__ Fair
__ Somewhat poor
__ Poor
__ Very poor
Or we might use this scale:
Q: Would you say your health is:
__ Excellent
__ Very good
__ Good
__ Fair
__ Poor
__ Very poor
__ Terrible
In my book, in chapters 9 and 11, I write about how to make questions unbiased. Making bipolar scales balanced is critical.
The midpoint, “Fair,” may be better labeled, “Neither good nor poor,” or it might make sense to leave out the midpoint and force respondents to lean in one direction or the other, as we often do in attitude measurement.
