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Marketing for Dummies cover
global pct
3.3

Book

Marketing for Dummies

Two parallel scores from 3 calibrated reviewers and 5 raw-average reviewers.

3.3%
Z · Global
3.3%
Z · Cohort
16.5%
Raw · Global
16.5%
Raw · Cohort
Two scores · one item
Z-normalized · global
3.3
Z-normalized · cohortpublication decade
3.3
Raw average · global
16.5
Raw average · cohortpublication decade
16.5

Z-normalized corrects for reviewer bias (every reviewer re-centered onto their personal scale). Raw average uses simple mean across the broader pool including stddev=0 reviewers.

Where this book sits

0255075100

Z-normalized percentile · 5,285 ranked books

Mean reviewer z-score-1.198
Calibrated raw-mean rating4.00 /5
Broad raw-mean rating4.40 /5
90% CI-floor (z)-2.148
Reviewers (calibrated / broad)3 / 5

Summary

Marketing for Dummies sits at the 3th z-normalized percentile across 5,285ranked books. The z-percentile differs from a raw star average because Rankquant subtracts each reviewer's personal baseline before aggregating — so a reader who rates everything 5 stars carries less weight than one who rates discerningly. Raw-average percentile is 17; the gap between the two measures how much bias-correction changes this title's standing. How percentiles are computed.

Pipeline applied to this title

The math, in this order

01
Z-score per reviewer

3 reviewers with rating variance re-centered onto a personal z-scale.

02
Aggregate

Mean z = -1.198. Broad raw mean = 4.40/5.

03
CI-floor

90% CI-floor = -2.148. Thin samples penalized.

04
ECDF percentile

Global 3.3. Z-track and raw-track ranked separately.

Similar percentile

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