'Information retrieval based on historical data' (US7346839B2) is a Google patent filed in 2003 and granted in 2008, naming engineers including Matt Cutts, Jeff Dean and Paul Haahr. It describes scoring documents using history: when a document first appeared, how its content changes, and how links to it grow or spike. Google has not confirmed which parts, if any, are used. For a site, it is the origin of many freshness and link velocity ideas, and a reminder that cosmetic date changes are easy to discount.
What is the historical data patent?
The historical data patent is US7346839B2, Information retrieval based on historical data, assigned to Google. It has a priority date of September 30, 2003, a filing date of December 31, 2003 and a grant date of March 18, 2008, per Google Patents.
The inventors are Anurag Acharya, Matt Cutts, Jeffrey Dean, Paul Haahr, Monika Henzinger, Urs Hoelzle, Steve Lawrence, Karl Pfleger, Olcan Sercinoglu and Simon Tong, a list that includes Google's head of webspam at the time and several senior search engineers.
A system identifies a document and obtains one or more types of history data associated with the document. The system may generate a score for the document based, at least in part, on the one or more types of history data.
Google (patent), US7346839B2: Information retrieval based on historical data, Google Patents
What historical signals does the patent describe?
The patent lists many kinds of history data. The ones most discussed in SEO are:
- Inception date: when the document was first seen, used for example to compute the rate at which links to it are created.
- Content updates: how often and how much the content changes, weighting changes to main content above changes to boilerplate.
- Link history: how the number and rate of back links change over time, as a freshness signal and as a spam signal.
- Domain information: registration and hosting details, including when a domain expires and a different party buys it.
By analyzing the change in the number or rate of increase/decrease of back links to a document (or page) over time, search engine 125 may derive a valuable signal of how fresh the document is.
Google (patent), US7346839B2: Information retrieval based on historical data, Google Patents
What evidence is there that Google uses historical data?
The evidence label is patent only. The patent describes possibilities in broad terms using "may", and Google has not said which of them are in production. Some related concepts are confirmed separately: Google names freshness systems in its ranking systems guide, but that does not confirm this patent's specific methods.
Treat claims such as "Google penalises domains registered for only one year" as unproven readings of this patent, not established facts.
A large spike in the quantity of back links may signal a topical phenomenon (e.g., the CDC web site may develop many links quickly after an outbreak, such as SARS), or signal attempts to spam a search engine
Google (patent), US7346839B2: Information retrieval based on historical data, Google Patents
What does the historical data patent mean for my site?
The most practical passage is about what counts as a change. The patent says updates to low-value elements, including date/time tags, may be given little weight or ignored. Changing a page's visible "updated" date or sitemap lastmod without changing the substance is the pattern that description predicts will be discounted.
A falsifiable test: diff the main content of pages whose visible date changed in the last 90 days against an archived copy from before the change. If most date changes coincide with no substantive content change, the dates are not carrying the information they claim.
Content deemed to be unimportant if updated/changed, such as Javascript, comments, advertisements, navigational elements, boilerplate material, or date/time tags, may be given relatively little weight or even ignored altogether when determining UA.
Google (patent), US7346839B2: Information retrieval based on historical data, Google Patents
Which Laurelin audit checks test for historical data signals?
The new check, visible updated dates change without substantive content change, tests the date-change pattern described above. It measures the pattern the patent describes, not whether Google applies it.
Related existing checks:
- Lastmod missing or always now: the sitemap version of an unreliable date.
- Outdated content: the opposite failure, genuinely stale content.
- No last reviewed or updated date on time-sensitive content: honest dates help readers and systems.
- Unnatural link velocity: the link spike pattern the patent associates with spam.
- Expired domain parasite abuse: the patent discusses domains that expire and change hands.
What are the key dates for Google historical data patent?
Frequently asked questions about Google historical data patent
Who wrote Google's historical data patent?
US7346839B2 names ten inventors including Matt Cutts, Jeffrey Dean, Paul Haahr and Monika Henzinger. It was filed in December 2003 and granted in March 2008.
Does changing the date on a page help rankings?
There is no evidence it does. The historical data patent says changes to date/time tags may be given little weight or ignored, and Google has not confirmed any benefit from date changes alone.