of a variable determines how we can assign numbers to its values, and how meaningful computations with those numeric values are. For instance, if you determine whether people are male or female, you can assign numbers to this variable “biological sex”, such as <span class="math inline">\(\text{female} = 2\)</span> and <span class="math inline">\(\text{male} = 1\)</span>, but it doesn’t make that much sense to treat these numbers in the usual way. For instance, that we assigned a higher value to female