Methodology changelog

Luce's methodology identities, grammar changes and statistical publication rules. Cite a measured figure with the methodology identity in its wave or reproducibility bundle, its interval, its sample and its provenance. The methodology page describes the rules; this register records their changes.

Dates below are repository change dates. They establish when code changed; they do not establish when a deployment used it. Historical entries were reconstructed on 7 September 2026 from the referenced revisions. Several changes retained the same methodology identity. A version alone therefore cannot distinguish every historical grammar revision. The wave's prompt identifiers and retained bundle provide the additional evidence available for a citation.

Published by Veliu Research Lab. Veliu sells services to brands measured here.

2026-09-07: source audit and public register

Authored record. This register opens with the historical changes below. Publishing the register changes distribution; it introduces no statistical threshold or new measurement. The current wave's methodology identity is printed by the page from the served wave metadata.

Derived check. The source fingerprint covers production code in the grammar, statistics, marts, schema and extraction packages, plus the live basket, API runner and consumer/API divergence estimator. It is a source revision identifier, with no measured quantity or confidence interval. A changed fingerprint requires a dated entry describing what moved. The build also checks that each methodology identity declared by code and each served or retained wave has an authored entry. The statically imported public document is checked byte for byte against its Markdown source.

Source fingerprint: 0169de28611e46bd972509d429a6908097b38ada749bc4dbdb0c29d9ce9fe1e8

2026-09-07: the basket generator enters the grammar

Authored record. The grammar gained a deterministic generator for localized L3 prompt baskets, keyed on a (sector, market) pair and a recorded seed, so the same input produces the same basket and a published basket can be re-derived from its seed. Nothing about an existing basket moved: the baskets this board has already measured are unchanged, and the generator produces new ones for sectors that have not been measured yet.

No threshold moved. The gates that decide what is publishable keep the values they had, and the scaling ladder that governs which sectors may be measured is a separate control with its own record.

2026-09-06: divergence estimator and unresolved intervals

Authored record, revision 0cd9e32. The consumer/API Divergence Index gained a joint prompt-cluster bootstrap interval. Its estimate is one minus the Jaccard overlap of the two top shelves. A resample with an empty shelf has no index and is excluded from its interval. Publication checks reconstruct the shelves from the same evidence as the published cells. The estimator uses 500 outer and 300 inner replicates, with seed 1. At least 0.99 of the outer replicates must yield a defined index for publication. An unresolved zero-width interval in an underpowered cell is disclosed as unresolved. Retained bundles carry their own methodology identity, rates, intervals and evidence identifiers.

The served pilot kept luce-live-v0. This was an estimator and publication change under that existing identity. The retained wave payload establishes which figures were published.

2026-08-31: cohort audit estimator

Authored record, revision cb0d204. The statistics package added a cohort difference-in-differences audit with brand-clustered uncertainty and Student-t intervals, a parallel-trends check requiring at least three pre-treatment waves, and a placebo panel requiring at least four. Its default alpha is 0.05. These are capabilities of the code. This entry establishes no published cohort result. The board's declared pilot methodology identity remained luce-live-v0.

2026-08-27: cohort publication gates

Authored record, revisions c21f9d1 and 5b3ceca. Cohort publication moved to predefined cells. The membership floor is 20. The initial pairwise separation rule was replaced by a check over combinations of admitted cells: a nonempty support below five members is refused. Admission is capped at 12 cells per context. Exact counts and order statistics were removed; count bands are 20-29, 30-49, 50-99 and 100+. Grid values use the same wave, surface and provenance tier as their source cells. These code gates establish no published cohort result and made no change to the pilot's declared methodology identity.

2026-07-15: localized and expanded live baskets

Authored record, revision acd6b46. The running-shoes and wireless-earbuds baskets expanded from en-US to separately authored it-IT and de-DE prompts. Each basket carries 30 prompts. The runner keeps markets separate in the published cells.

Authored record, revision 7eca662. The basket added coffee-machines, robot-vacuums and air-fryers, with 12 prompts per category and locale, and the consumer web capture path. A basket's existence establishes a probe design; captured evidence determines what appears on a board. Both changes retained luce-live-v0.

2026-07-11: live pilot methodology

Methodology identity: luce-live-v0

Authored record, revision 76e2982. The pilot introduced a fixed unbranded basket with 30 prompts per category, initially running-shoes and wireless-earbuds in en-US. Prompts are L3 synthetic; actual engine responses are L1 elicited. Each engine surface has its own cells. Relative precision controls settled league membership, and underpowered cells retain their rates and intervals with a measuring state. The dates and identities on a wave describe that wave's measurements.

2026-07-10: statistical and grammar baseline

Methodology identity: v0

Authored record, revisions 92ae1da, e884a30 and 605cc77. The baseline introduced the joint prompt-cluster bootstrap, rank ranges, leagues, movement gates and the six-family grammar. The MCP methodology description declares v0; that identifier describes the tool's methodology text. A measured wave carries its own methodology identity.

The baseline sizing defaults use z=1.96 and a relative interval half-width of 0.25. League assignment defaults to a minimum observed rate of 0.05 and maximum relative half-width of 0.25. Movement defaults require four waves, false-discovery q=0.05, change-point z=2.5 and a minimum segment of two waves. The grammar's unbranded-share bounds are 0.55 and 0.60. These are source defaults, separate from the parameters a particular wave may supply. A bundle whose gate parameters are absent continues to disclose that absence.

2026-07-10: illustrative renderer identity

Methodology identity: 0.3-sample

Authored record, revision b2408fb. This identity belongs to the existing illustrative renderer fixture. Its banner identifies its fictional data, and it is excluded from indexing. It establishes no live measurement and belongs to no measured pilot result.

Served wave methodology: luce-live-v0.