Six Sigma at Cuzco

Claim (verbatim)

Six Sigma at Cuzco. Joins statistical process control — the control charts and capability indices of modern manufacturing — to Andean ceramics. Inca state pottery, above all the standard aryballos storage jar, was the output of an administered production system, so the tightness of its dimensional tolerances should measure how firmly the administration gripped the workshop. Near Cuzco, state supervision of attached potters could enforce tight specifications; down the provincial hierarchy, supervision thinned and imitation crept in, so variance should loosen with distance from the capital. The conjecture predicts that the coefficient of variation of rim diameter and height within a size class is small for Cuzco-region aryballoi and roughly doubles for distant provincial imitations, increasing monotonically with distance from Cuzco across several regions — while co-occurring local non-state wares show no comparable gradient, isolating administrative reach rather than potter skill as the cause.

Prediction clause (verbatim)

For imperial-style aryballoi, the coefficient of variation of rim diameter and of height within a size class is <=6% for Cuzco-region production but >=12% for distant provincial imitations, with CV increasing monotonically with distance from Cuzco across at least four regions (Cuzco heartland, Titicaca basin, Ecuador highlands, coastal enclaves); co-occurring local non-state wares show no comparable gradient, isolating administration rather than potter skill as the cause.

Kill-dataset (verbatim)

Kill: published metric datasets of provenienced aryballoi (museum and excavation catalogues). A flat CV-versus-distance profile, or provincial CVs matching Cuzco within 2 percentage points, kills it.

Novelty / leakage triage

already answered in the literature

The standardization-gradient-from-Cuzco is an established archaeometric finding: Lara & Bray show Ecuadorian provincial Inca-style ceramics are more standardized than local wares but LESS uniform than Cuzco's, with distant production 'less regulated'; Cuzco-region petrography documents centralized quality control. The published metric is compositional rather than the conjecture's dimensional CV — a refinement, not a new connection.

• Lara & Bray, 'Imperial Inca-style pottery from Ecuador: INAA and ceramic petrography' — The gradient finding, compositional metric

Predictions

No prediction registered yet.