Wright's law in clay

Claim (verbatim)

Wright's law in clay. This joins Wright's law — the industrial learning curve, under which performance improves as a power law of cumulative production — to the humblest of ancient mass products, amphorae and lamps. Wright's law is usually treated as a discovery of twentieth-century aircraft manufacture, but its mechanism is generic: every unit made is practice, and practice tightens tolerances. If ancient workshops learned the same way, then dimensional standardization — measured as the coefficient of variation (CV) of amphora and lamp dimensions — should fall as a power law of cumulative regional output, exactly the functional form of the modern learning curve, two millennia early. The prediction is quantitative and directional: regions and periods with larger cumulative production should show proportionally tighter CVs, the decline tracing a straight line on log-log axes rather than a loose downward drift with calendar time.

Prediction clause (verbatim)

For each regional ceramic industry in a dataset joining typology metrics to production estimates, compute the coefficient of variation of key dimensions (amphora height and capacity, lamp diameter) per period, and estimate cumulative output to that period; fit log(CV) against log(cumulative production) across periods and regions. Primary clause: the fitted relation must have a significantly negative slope with the power-law (log-log linear) form explaining at least half the variance in CV; if CV shows no dependence on cumulative output, or declines only with calendar time regardless of production volume, the claim fails. The verdict follows the primary clause.

Kill-dataset (verbatim)

typology metrics vs production estimates.

Novelty / leakage triage

already answered in the literature

The connection between production intensity/scale and dimensional standardization (measured by coefficient of variation) is an established research program in archaeological ceramics — the standardization hypothesis literature states substantially this join, including for amphorae and with explicit production-scale studies. The Wright's-law functional form (CV as a power law of CUMULATIVE output) is the only unlocated refinement.

• Roux, 'Ceramic Standardization and Intensity of Production', American Antiquity — The standardization-production join
• Eerkens & Bettinger, 'Techniques for Assessing Standardization in Artifact Assemblages', American Antiquity — CV methodology

Its literature citations feed the frontier as source leads (2 leads below the evidence/publication boundary, not yet reviewed).

Predictions

No prediction registered yet.