How and when to use unipolar answer scales (e.g., "never" to "all the time") 🔗

Although a seven-point scale is recommended for double-sided scales (good to bad, agree to disagree, etc.), for single-sided scales (e.g., "never" up to "all the time," "none" up to "all," etc.) a five-point scale is often desirable. This is because it's hard to come up with (and for participants to distinguish between) seven reasonable options to label for one-sided scales.

Note that in one-sided scales, numerical values should generally have the same sign, e.g., 0, 1, 2, 3, 4.

Good unipolar scale use examples 🔗

Here are some good examples of when and how to use unipolar scales:

>> ratingScale = [["Not at all", 0], ["A little", 1], ["Moderately", 2], ["Very", 3], ["Extremely", 4]]

*question: On a *typical* day, how tired or sleepy do you feel throughout the day over the past month?
	*answers: ratingScale

*question: On a *typical* day, how happy do you feel when you wake up?
	*answers: ratingScale

Bad unipolar scale use examples 🔗

Here's a bad example of a bipolar scale that would have worked better as a unipolar one:

>> ratingScale = [["Not at all", -2], ["Barely", -1], ["Somewhat, but not a noticeable amount", 0], ["A slightly noticeable amount", 1], ["Moderately", 2], ["Very", 3], ["Extremely", 4]]

This scale uses negative numbers for some parts of what should really be a one-sided scale. It also contains categories that would be difficult for most people to reasonably distinguish between (e.g., "Barely" vs "Somewhat, but not a noticeable amount").


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