Stat Unit

We also use Levels of Measurement to determine the appropriate measure(s) of central tendency. As we shall see, the relationship between measurement level and central tendency will also serve to focus our choices.

Recall, at the nominal level of measurement we have no underlying mathematical properties. Hence, neither the median nor the mean can be used with nominal level variables, as both of these measures require mathematical properties.

However, we can use the mode with nominal level variables. Consider the following example:

Sex Male Male Male Female Female

In this distribution, we have 3 males and 2 females. Hence the modal sex is male -- i.e. the sex that occurs most often.