What grade is it actually taught in?

Take Wonder. Ask the internet what grade it is for and you get one number. Ask 148 real assignment records across 29 states and 30 separate source documents, and you get grades 3–7— a five-grade window with its centre at grade 5. Both answers are “right”; only one of them tells a parent what will actually happen.

How much do schools disagree?

Spread is the distance between the lowest and highest grade a book is assigned in. A spread of 0 means every state that assigns it puts it in the same grade. A spread of 4 means it is taught across five grades.

Highlighted rows are books taught three or more grades apart — the majority of the corpus.

Are the publishers wrong? No.

The tempting story here is that published grade bands are inaccurate. We tested it, and it is false. Across 1,597 comparable books the median difference between the observed placement and the published band is 0 grades, and only 45 books diverge by a full grade or more. Publishers are right on average.

The problem is not accuracy, it is width. A single band collapses a genuine 4-grade range into one label, so it is correct about the centre and silent about the variation that actually affects a specific child in a specific classroom.

The books schools disagree about most

Widest observed spreads, restricted to books with at least 20 assignments so the range reflects real disagreement rather than a couple of outlying documents.

The most-assigned books, and where they land

The titles a parent is most likely to meet, with the grade window each one actually occupies.

Every title links to its full assignment record — which states, which grades, which source documents.

Methodology

The corpus is 13,258 assignment records collected from US state reading lists, district curriculum documents and state award programmes. Every record carries the URL and title of the document it came from; nothing is inferred from a difficulty score and nothing is generated.

For each book we take the minimum, maximum and median grade across all of its records. Spread is maximum minus minimum. A book enters the study only at 3 or more assignments, so that a spread reflects genuine disagreement between schools rather than one unusual document. That floor leaves 1,597 books.

Published grade bands, where a book has one, are compared against the observed median. We report that comparison whichever way it comes out — in this case it did not support the more eye-catching headline, so the page says so.

Figures on this page are committed alongside the code rather than recomputed on each build, so a number quoted from here will still be the same number later. Regenerate with scripts/compute-what-grade-is-it-taught-2026.py.

Download the data

All 1,597 books, with published band, observed range, median, spread, assignment count, distinct states and distinct sources. Free to use with attribution (CC BY 4.0).

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Cite this study

Related

• Which books America’s schools assign most
• How old are the books schools assign
• How long the assigned books are
• Reading lists by grade

Last verified 2026-07-31. Page built 2026-06-20T00:00:00.000Z.