Quantifiability refers to the ability to refer to or describe something in terms of numbers, rather than in terms of qualitative descriptions.
Sociologist George Ritzer argues that, under consumer culture, things that cannot be quantified are systematically devalued. We measure human worth by income; the value of a meal by portion size; risk by cost/benefit analysis, pitting quality of life against cold cash. Numbers offer a seductive objectivity in making decisions: more is better. The chain with the most stores must be the best. We buy, not the best-tasting sandwich, but the one with the largest pile of unidentifiable ground meat. In the process, we often forget about quality, especially quality of life.
Reflective design aims to question the naturalness of quantifiability, encouraging users to reflect on the extent to which numbers really sum up their lives. The user is put into a situation where quantifiability is pushed to extremes, showcasing the ways in which it can be pathological. For example, the Tenure Ticker highlights the illusion that the frightening and mysterious tenure process can be controlled and understood by reducing quality of intellectual output to an equation. Alternatively, technology designs can suggest ways in which quantified values can be unpacked, as in clocks that measure a personal, subjective time by counting a user's heart beat or breath rate.