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surprise concept

DefinitionMinus the log base two of an outcome's probability, its information in bits. Certainty carries none, a fair coin's outcome one bit, and one chance in eight three. Primer S, equation S.19.
ExampleAn outcome with probability one eighth carries 3 bits.
BookData Mining as Observation, draft 0.2, commit f3914f0; entry id surprise, kind concept.
Statusno ledger row names this entry. Corrections: none recorded.
Defining equation

Book equation S.19.

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

Book equation S.19.

\[H(p)=-\sum_i p_i\log_2 p_i.\]

Conditions

none

Ledger

none

First stated

Primer S section S.10 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

none

Failures and corrections

none

Invariance envelope

none declared

Machine checked

none

Used in

Data Mining as Observation primer S, chapters 5.

Related

entropy; bit.

See also

none

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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