Archived catalog comparison finds 46.4% URL overlap
July–August 2026 analysis dates · National source corpora; sampled districts UT/AZ/GA/PA/ID
The archived URL comparison can now be reproduced. Its counts and cleaning limits are linked below.
Documented calculation
Who and what is involved
- Institutions
- Project verification work; private report collections
- People and recorded roles
- Researchers; report authors unresolved
- Organizations, bodies and vendors
- RatedBooks; BookLooks; sampled school districts
- Laws, rules and procedures
- District policies checked separately
- Products and information systems
- CDX URL slugs; report PDFs; editions; five-district sample
Sources
Earlier research pages
Open question
Can title/edition/report versions and a public methods exhibit support each count without changing denominators?
Where this appears
Evidence relationships that use it
The archived overlap analysis can now be inspected
Research update · October 15, 2026
Re-running the saved August 2026 analysis on October 15 reproduced 566 matching normalized URL slugs out of 1,220 cleaned RatedBooks slugs, or 46.4%. Of the 846 first captured before BookLooks’ March 23, 2025 shutdown, 565 match; of the 374 first captured on or after that date, one matches.
This is a comparison of archived URL names. Normalization can combine different works, and the cleaning rules discard some short names. A first archive capture is not a publication date. These counts measure overlap in the selected archived sets, rather than copying, report authorship or a complete catalog.
Inspect the inputs, calculation and limits. The earlier citation and five-district studies remain separate checks; their results are not included in this overlap count.