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Dear Debbie cover
global pct
30.1

Book

Dear Debbie

Two parallel scores from 9 calibrated reviewers and 21 raw-average reviewers.

30.1%
Z · Global
30.1%
Z · Cohort
25.4%
Raw · Global
25.4%
Raw · Cohort
Two scores · one item
Z-normalized · global
30.1
Z-normalized · cohortpublication decade
30.1
Raw average · global
25.4
Raw average · cohortpublication decade
25.4

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-0.119
Calibrated raw-mean rating4.44 /5
Broad raw-mean rating4.57 /5
90% CI-floor (z)-0.667
Reviewers (calibrated / broad)9 / 21

Summary

Dear Debbie sits at the 30th 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 25; 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

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

02
Aggregate

Mean z = -0.119. Broad raw mean = 4.57/5.

03
CI-floor

90% CI-floor = -0.667. Thin samples penalized.

04
ECDF percentile

Global 30.1. Z-track and raw-track ranked separately.

Similar percentile

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