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anti-hub recall instrument

DefinitionRecall at k restricted to the rows that are rarely retrieved, the observer's outliers, reported as the minimum over strata so that a mean cannot hide the tail. Chapter 10.
ExampleSeven strata of rarely retrieved rows scored between 0.62 and 0.69, so the minimum, 0.663, failed the bar of 0.90.
BookData Mining as Observation, draft 0.2, commit f3914f0; entry id anti-hub-recall, kind instrument.
Statusno ledger row names this entry. Corrections: none recorded.
Defining equationnone
Assumptions and scope
  • Recall at k restricted to the rows that are rarely retrieved, the observer’s outliers, reported as the minimum over strata so that a mean cannot hide the tail. It lies in the unit interval and is one exactly when every anti-hub’s true neighbours are returned.
  • Compressed indexes fail on anti-hubs first while aggregate recall barely moves, and the remedy that promotes isolated rows is the remedy that compression damages first, which is why the gate is a build gate and not a report line.
Prior artnone recorded
Evidenceturboquant-pro/docs/HUBNESS_PRIMER.md:86-131, lean/DataMiningAsObservation/RecallAtK.lean, lean/DataMiningAsObservation/Hubness.lean
Reviewednot yet reviewed; generated 2026-09-10 from records at the commits on the provenance page.
00.51stratumscores1s2s3s4s5s6s7barmean passes, the minimum fails
Recall on the rarely retrieved rows, taken as the minimum over strata.

Equation

none

Conditions

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

Ledger

none

First stated

Chapter 10 section 10.2 of Data Mining as Observation, with the program’s gate in turboquant-pro/docs/HUBNESS_PRIMER.md:86-131 and the strata result in turboquant-pro/docs/RESULTS_strata_phase23_gates.md.

Measurements

Where the book states it Numbers, as the book’s sources table records them Source
chapter 11 section 11.6 anti-hub recall, p05, hub-rank correlation, hub-set overlap, the build gate turboquant-pro/docs/HUBNESS_PRIMER.md:86-131

Failures and corrections

none

Invariance envelope

none declared

Machine checked

lean/DataMiningAsObservation/RecallAtK.lean, theorems recallAtK_mem_unit, recallAtK_eq_one_iff, aggregate_le_of_failing, aggregate_example, at observation-data-mining f3914f0; what the check covers is stated in the book’s appendix C.

lean/DataMiningAsObservation/Hubness.lean, theorems sum_count, sum_count_eq, count_congr, antiHub_iff, at observation-data-mining f3914f0; what the check covers is stated in the book’s appendix C.

Used in

Data Mining as Observation chapters 10, 11, 12.

Related

anti-hub; recall at k; min-over-strata; hub; stratification.

See also

Book equations stated beside the entry’s terms, not defining it: 10.7, 11.3, 0.35.

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 10.2, chapter 10 section 10.4, chapter 10 section 10.5, chapter 12 section 12.4.

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.

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