The Observation Theory EncyclopediaFrom TSKAboutBy kindBy chapterBy Lean fileLedgerProvenance

detector instrument

DefinitionA scorer that calls a row an outlier, of four families reading distance from the mean, distance to neighbours, density relative to neighbours, or cluster membership. Chapter 10 section 10.1.
ExampleA row 3.6 spreads from the mean is an outlier to the statistical detector and may be ordinary to the density detector.
BookData Mining as Observation, draft 0.2, commit f3914f0; entry id detector, kind instrument.
Statusno ledger row names this entry. Corrections: none recorded.
Defining equationnone
Assumptions and scope
  • A scorer that calls a row an outlier, of four families. The statistical detector reads distance from the mean in units of spread, the proximity detector reads distance to neighbours, the density detector reads density relative to neighbours, and the clustering detector reads membership. Each reads a coordinate the others discard.
  • No detector of the data alone sees the observer’s outliers, the anti-hubs, because they are a property of the queries, and a detector’s positives are few by Chebyshev’s arithmetic.
Prior artnone recorded
Evidencelean/DataMiningAsObservation/Outlier.lean, lean/DataMiningAsObservation/Mahalanobis.lean, lean/DataMiningAsObservation/Dbscan.lean
Reviewednot yet reviewed; generated 2026-09-10 from records at the commits on the provenance page.
outlieroutlier
A scorer that calls a row an outlier, of four families.

Equation

none

Conditions

Conditions are curated in entries.toml rather than read from a record.

Ledger

none

First stated

Chapter 10 section 10.1 of Data Mining as Observation, after TSK chapter 9, with the hierarchical typing in turboquant-pro/turboquant_pro/anatomy.py:98-170.

Measurements

Where the book states it Numbers, as the book’s sources table records them Source
chapter 10 section 10.1 the four detector families TSK 2e chapter 9

Failures and corrections

none

Invariance envelope

none declared

Machine checked

lean/DataMiningAsObservation/Outlier.lean, theorems zscore_mean, zscore_affine, outlier_iff, zscore_reflect, chebyshev, at observation-data-mining f3914f0; what the check covers is stated in the book’s appendix C.

lean/DataMiningAsObservation/Mahalanobis.lean, theorems dM2_nonneg, dM2_mean, dM2_scale, dM2_eq_whitened, dM2_antitone_in_variance, at observation-data-mining f3914f0; what the check covers is stated in the book’s appendix C.

lean/DataMiningAsObservation/Dbscan.lean, theorems ball_mono, core_mono, core_anti, reach_from_core, noise_unreachable, at observation-data-mining f3914f0; what the check covers is stated in the book’s appendix C.

Used in

Data Mining as Observation chapters 3, 8, 10, 13.

Related

outlier; Mahalanobis distance; density; DBSCAN; anti-hub.

See also

Book equations stated beside the entry’s terms, not defining it: 0.33, 10.3, 9.1.

Ledger rows that cite the entry’s records without naming it: NEG-14.

Sources-table rows that share a record with the entry without naming it: chapter 10 section 10.3.

Status

Generated 2026-09-10 by encyclopedia/generate.py; book at observation-data-mining f3914f0; the commit of every record is listed in the encyclopedia’s provenance.

← deployment mismatchdeterminant →