Counselor Education Comprehensive Exam (CECE) Practice Exam

Which type of scale has equal distances between points and an absolute zero?

1. Nominal scale

2. Ordinal scale

3. Interval scale

4. Ratio scale

The correct answer is: Ratio scale

The ratio scale is the correct choice because it possesses both equal intervals between points and a true absolute zero. This means that not only can you measure the distances between values, but zero indicates a complete absence of the quantity being measured. For example, in a ratio scale measuring weight, a weight of zero means there is no weight at all, and a weight of 10 kg is twice as heavy as 5 kg, reflecting the absolute differences in measurement. In contrast, nominal scales categorize data without any order or distance between categories, such as gender or hair color. Ordinal scales do provide a rank order of data but do not have equal spacing between points, as they indicate relative positioning rather than precise measurements. Interval scales feature equal distances between points, allowing for meaningful comparisons, but they lack a true zero point, which means the absence of the quantity cannot be measured—temperatures in Celsius are an example of this, where 0 degrees does not indicate 'no temperature' but rather is just a point in the scale. Thus, the defining characteristics of the ratio scale make it unique for precise measurement and comparison in data analysis.