Certified Rehabilitation Counselor Practice

Which scale is characterized by having no arbitrary zero point?

1. Ordinal scale

2. Nominal scale

3. Ratio scale

4. Interval scale

The correct answer is: Ratio scale

The scale that is characterized by having no arbitrary zero point is the interval scale. This type of scale allows for the measurement of the difference between values, but it does not support the concept of a true zero point, which indicates the absence of the quantity being measured. For example, in temperature measured in Celsius or Fahrenheit, a temperature of zero does not mean there is no temperature; rather, it is merely a point on the scale. In contrast, a nominal scale categorizes data without any quantitative value or order, while an ordinal scale ranks data but does not express how much more one item has than another. The ratio scale, on the other hand, does have an absolute zero point, allowing for a comparison of absolute magnitudes. Therefore, the defining characteristic of the interval scale is its lack of an absolute zero, making it the correct choice in this context.