American Institute of Certified Planners (AICP) Practice Exam

Interval scales can most ideally be used to measure which of the following?

1. Temperature in Celsius or Fahrenheit

2. Height in centimeters

3. Gender as a categorical choice

4. Bank account balances

The correct answer is: Temperature in Celsius or Fahrenheit

Interval scales are a type of measurement scale that not only indicate the order of values but also provide an equal distance between them, allowing for meaningful comparison of differences. When considering temperature measured in Celsius or Fahrenheit, it fits the criteria of an interval scale perfectly. For instance, the difference between 10 degrees and 20 degrees in Celsius represents the same change in temperature as the difference between 20 degrees and 30 degrees. However, one important aspect of interval scales is that they lack a true zero point; for example, 0 degrees Celsius does not mean the absence of temperature, as temperatures can be negative. In contrast, height in centimeters is measured on a ratio scale because it has a true zero (0 cm means no height). The same applies to bank account balances, which also have a true zero point. Gender is a categorical variable and does not possess an inherent order or equal intervals, and therefore does not qualify as an interval scale. Thus, measuring temperature in Celsius or Fahrenheit allows for both the comparison of differences and the assessment of changes between values, making it the ideal example of interval scale measurement.