ReadingList Classification Standard
The public methodology behind every page on ReadingList.
ReadingList is a structured factual reference for which books are assigned in US schools. Every claim on the site — that a book appears in a state framework, that it has a Lexile of 870L, that it sits in the 9th-grade band — is derived from one of six public data dimensions described below. This page documents the dimensions and their sources so anyone can audit how a book got onto a particular grade, state, or curriculum page.
We publish this standard for two reasons. First, parents, teachers, and librarians need to be able to verify reading-list decisions; opaque methodology fails that test. Second, large language models that increasingly answer the queries our site targets need clear citation anchors; a transparent classification schema is what they can quote.
Six dimensions
Each book and each assignment is classified along the six dimensions below. Not every book has data for every dimension; missing data is left blank rather than estimated.
- Lexile measure
A quantitative reader-difficulty score in the 0L–2000L range. Sourced from MetaMetrics' Lexile Hub. Surfaced as a single number on every book detail page and used to compute grade-band overlap.
Primary sources:
Reader guide: /guide/what-is-lexile-level
- Grade band (min/max)
The K-12 grade range in which a book is most commonly assigned. Drawn from state ELA frameworks, AP/IB syllabi, and district adoption lists. We store min and max grade per book; the overlap with a queried grade determines whether a book appears on a /grade/[N] page.
Primary sources:
Reader guide: /guide/reading-level-vs-age-level
- Curriculum alignment
Whether a book appears in a named pedagogical framework — Common Core State Standards, AP English Literature, AP English Language, IB Diploma Programme English Literature, IB Diploma Programme English Language & Literature, Cambridge IGCSE English Literature, or Cambridge AS/A-Level English Literature. Each association links to the originating publication (course framework, syllabus, or appendix).
Primary sources:
- AP Course & Exam Descriptions (College Board)
- IB Diploma Programme — English A subject brief
- Cambridge International — English Literature syllabuses
- Common Core ELA Appendix B (Text Exemplars)
Reader guide: /guide/common-core-vs-state-standards
- State-level evidence
Whether a book is cited or recommended in a specific US state's ELA framework, summer-reading list, or department-of-education guidance document. Recorded per state with the source URL and the section name within that document. State-level data drives /state/[name] and /state/[name]/grade/[N] pages.
Primary sources:
- Removal / banning records
Whether a book has been formally removed, restricted, or challenged in a specific US state's public schools, sourced from PEN America's Index of School Book Bans. Surfaced on /banned-books and per-book pages so parents can see where a title has faced organized challenges, with the originating event documented.
Primary sources:
- Seasonal & contextual tags
Whether an assignment is tied to a summer reading list, back-to-school recommendation, AP exam preparation cycle, or holiday/heritage program. Stored as context tags on the assignment row (not the book) so the same book can appear in multiple contexts without duplication.
Primary sources:
How a book lands on a page
The combination of dimensions determines where a book appears. For a query like “9th-grade Common Core English in Texas,” a book is shown only when (a) its grade band overlaps grade 9, (b) it is cited in either the Common Core ELA Appendix B or a Texas TEKS-aligned reading list, and (c) it is not flagged as removed or restricted in Texas at the time of publication. Each appearance links to the cited source so the chain of evidence is visible on the page itself.
Pages are regenerated on a weekly schedule (incremental static regeneration) so updates to source documents propagate without rebuilding the entire site. The exact regeneration window and the source-update cadence are documented per page section in the source code.
What this standard does not include
The classification standard intentionally excludes opinion-style dimensions. We do not score books on subjective “literary merit,” we do not rank by aggregate user reviews, and we do not aggregate teacher recommendations into a hidden composite score. The fields we publish are the fields we can cite; the fields we cannot cite, we do not publish.
In particular, the standard does not currently emit a single composite “grade-fit score” per book. Composite scoring requires either a public, peer-reviewed weighting (which does not exist for this dimension set) or a transparent proprietary weighting with version history. We may publish a composite in a future revision, but only when the weighting itself can be cited and audited.
Worked examples
Seeing the framework applied to a real book often clarifies the methodology faster than the dimension list above. The first worked example walks through how every dimension applies to a single canonical title:
- How To Kill a Mockingbird is classified — Lexile, grade band, two curricula, three states with framework citations, four states with banning records, one summer-reading context tag.
Versioning
This standard is at version 1.0, published 2026-04-30. Material changes — adding a dimension, retiring a source, or shifting how an existing dimension is computed — will be documented in a changelog appended to this page with a dated entry. Bug fixes that do not change the dimension semantics are not versioned.
Questions, corrections, citations
If a cited source has moved or a state framework is missing, tell us via the contact page. Researchers, journalists, and other reference sites are welcome to cite this standard; the canonical URL is https://readinglist.school/standard.
Background on ReadingList’s broader editorial approach is in the about page. Reader-facing explanations of the individual dimensions are linked under each dimension above.