Issues of Measurability

Issues of Measurability
The above example of classifying facial photographs into different categories of emotions is an example of a qualitative classification of the basic observations. Although qualitative categories and qualitative variables are perfectly valid in the physical, biological, and social sciences,
theories and hypotheses are most powerful when they involve quantitative independent and dependent variables. Many economists are of the opinion that economics has a more impressive scientific track record than anthropology because economists work with numerical
variables such as prices, quantities, and income, rather than with qualitative variables like trust, group identification, or loyalty. Most theories and hypotheses involving quantitative independent and dependent
variables are easier to test, to fine tune, and if necessary, to revise, than most theories and hypotheses involving qualitative variables.
Is uncertainty an inherently qualitative or quantitative construct? In the following sections we shall see that one of the two primary methods
of representing uncertainty—the so-called “objective approach”— represents uncertainty quantitatively, via numerical probabilities. On the other hand, the other primary method—the so-called “subjective
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approach”—has traditionally represented uncertainty in a qualitative manner, via an unstructured set of states of nature. However, in the final section of this paper, we see that taking a measurable, quantitative approach to subjective uncertainty can enhance its power, and in many senses can serve as an almost complete substitute for what may be considered
the more ad hoc assumptions made about the world in the objective approach.