Book
First Grade Big Workbook Ages 6 - 7: 220+ Activities, Phonics, Spelling, Reading, Language Arts, Math, Space, Measurement and Time (Gold Stars Series)
Two parallel scores from 3 calibrated reviewers and 3 raw-average reviewers.
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. The 21-point gap is the rating-inflation signature for this title — the casual crowd liked it more than discriminating reviewers (a classic inflation pattern).
Where this book sits
Z-normalized percentile · 5,285 ranked books
| Mean reviewer z-score | +0.314 |
|---|---|
| Calibrated raw-mean rating | 5.00 /5 |
| Broad raw-mean rating | 5.00 /5 |
| 90% CI-floor (z) | -0.636 |
| Reviewers (calibrated / broad) | 3 / 3 |
Summary
First Grade Big Workbook Ages 6 - 7: 220+ Activities, Phonics, Spelling, Reading, Language Arts, Math, Space, Measurement and Time (Gold Stars Series) sits at the 62th 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 83; 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
3 reviewers with rating variance re-centered onto a personal z-scale.
Mean z = +0.314. Broad raw mean = 5.00/5.
90% CI-floor = -0.636. Thin samples penalized.
Global 61.9. Z-track and raw-track ranked separately.
Similar percentile
