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z-score concept

DefinitionA value with the mean subtracted and the result divided by the standard deviation, the number of standard deviations it sits from the mean. Standardizing a column is the same operation with the column's own mean and spread. Primer S section S.2.
ExampleA roll of six has z-score (6 - 3.5)/1.708 = 1.46.
BookData Mining as Observation, draft 0.2, commit f3914f0; entry id z-score, kind concept.
Statusno ledger row names this entry. Corrections: none recorded.
Defining equationnone
Assumptions and scopenone
Prior artnone recorded
Evidencenone
Reviewedsemantic review 2026-09-09; generated 2026-09-10 from records at the commits on the provenance page.

Equation

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Conditions

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Ledger

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First stated

Primer S section S.2 of Data Mining as Observation, added in draft 0.3 (2026-09-09) for the ECE 514 readers whose first courses are far behind. The idea is standard and TSK Appendix C covers it at length.

Measurements

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Failures and corrections

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Invariance envelope

none declared

Machine checked

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Used in

Data Mining as Observation primer S, chapters 10.

Related

standard deviation; standardization.

See also

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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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