Differential “progressibility” in human know-how: A conceptual overview

Over the last few hundred years, best practice in some fields of human action—e.g. the treatment of heart disease, the transportation of persons, goods, and messages, and destruction of landscapes, structures, and lives—has become dramatically more effective. At the same time, best practice in other fields, e.g. the amelioration of poverty or the teaching of reading, writing, or math, has improved more slowly, if at all. As Richard Nelson and colleagues have argued, it seems that practice and technology (“know-how”) can only improve rapidly under rather special conditions: that, at any given point in time, some fields are more “progressible” than others. Drawing on Nelson's work and studies in the history, sociology, and economics of technology and innovation, I offer a conceptual framework articulating several characteristics of practice in a field that may facilitate rapid progress. These characteristics, while not fixed, tend to remain fairly stable for long periods of time. I argue that know-how can improve more quickly 1) when “vicarious trial” of variations in practice is feasible and useful; 2) when practice is formal and standardized; 3) when practice is in significant part performed by artifacts rather than by humans; 4) when outcomes of variations in practice may be rapidly evaluated; 5) when valued performance dimensions are consistently agreed upon; 6) when contexts and objects of practice may be treated as, or have been made, consistent for the purposes of intervention; and 7) when labor is finely divided. Thus, analysis of these features may inform judgments about the plausibility of rapid advance within a field, absent disruptive change in methods or problem formulation. The argument may also shed light on which varieties of innovative effort may and may not foreseeably contribute to improving practice in a given field.