Interval scales are characterized by:

Interval scales are characterized by:

• A. A true zero point
• B. A natural order
• C. Equal intervals
• D. Unique categories with no numerical meaning

Answer: (C)

Interval scales are defined by equal spacing between adjacent values, so the distance from one point to the next is the same across the entire scale. That consistent difference lets you interpret how much two scores differ and to perform arithmetic like addition and subtraction on the values. The catch is that zero on an interval scale is not a true zero—it’s arbitrary and doesn’t mean “none of the quantity”—so ratios aren’t meaningful. That’s why a true zero point would indicate a ratio scale, not interval. Natural order alone points to ordinal scales, where only order matters, not equal intervals. And unique categories with no numerical meaning describe nominal scales, where numbers don’t convey magnitude at all. So the defining feature here is equal intervals.

Interval scales are defined by equal spacing between adjacent values, so the distance from one point to the next is the same across the entire scale. That consistent difference lets you interpret how much two scores differ and to perform arithmetic like addition and subtraction on the values. The catch is that zero on an interval scale is not a true zero—it’s arbitrary and doesn’t mean “none of the quantity”—so ratios aren’t meaningful. That’s why a true zero point would indicate a ratio scale, not interval. Natural order alone points to ordinal scales, where only order matters, not equal intervals. And unique categories with no numerical meaning describe nominal scales, where numbers don’t convey magnitude at all. So the defining feature here is equal intervals.