What changed, and when

Methodology and schema changes are versioned in the open, so a citation can be read against the rules that were in force when it was made.

How changes are tracked

Schema versions on the trial, manifest, and index files, bumped only on a breaking change, additive fields within a version.
Methodology version, bumped under public review when a metric definition or policy changes.
Algorithm versions: every sweep records the version of each algorithm it ran; the timeline below traces when each version was introduced.

The current versions are published at versions.json (see the data API). Each sweep's exact versions and build are preserved immutably under its own sweep page.

Dataset set changes

When the datasets of a scheduled sweep change, numbers before and after are on different datasets. Each change is listed here with what left, what replaced it and why; the trend charts mark the sweep it took effect on.

dataset Weekly set v2: from the next weekly sweep

Four datasets left the weekly set because their sources allow non-commercial use only, or give no permission without contacting the author. Their replacements were chosen by a rule fixed before any algorithm ran on them: the license permits commercial use and redistribution, with similar size and column types. Numbers before and after the change are on different datasets.

Left	Replaced by	Corpus
`vineyard`	`concrete_slump`	machine_building
`elusage`	`yacht_hydrodynamics`	machine_building
`analcatdata_vehicle`	`servo`	machine_building
`uscrime`	`daily_demand_orders`	finance

No sweep versions published yet.