The reasonable surfer model is described in Google patent US7716225, filed in 2004 by Jeffrey Dean, Corin Anderson and Alexis Battle. It replaces PageRank's random surfer, who clicks any link with equal probability, with one who is more likely to follow prominent, relevant links than footer or advert links. Google has not confirmed it uses this model. The practical lesson is still testable: put links to important pages where readers will actually use them, not only in boilerplate.
What is the reasonable surfer model?
The reasonable surfer model is a link weighting method described in Google patent US7716225, Ranking documents based on user behavior and/or feature data. It was filed on 17 June 2004 and granted on 11 May 2010, with Jeffrey A. Dean, Corin Anderson and Alexis Battle as inventors and Google as assignee, according to the Google Patents record.
It modifies the original PageRank idea. Where Brin and Page's random surfer follows every link on a page with equal probability, the reasonable surfer is more likely to follow some links than others.
This reasonable surfer model reflects the fact that not all of the links associated with a document are equally likely to be followed.
Jeffrey A. Dean, Corin Anderson and Alexis Battle (Google), US7716225B1, Google Patents
How does the reasonable surfer patent weight links?
The patent describes building a model from two kinds of data: features of each link and user behaviour data about which links people actually follow. The model predicts how likely a link is to be selected, and that probability replaces the equal split used in classic PageRank when computing a document's rank.
Features listed in the patent include the font size of the anchor text, the link's position (in a list, in running text, above or below the first screen, in a footer or sidebar), its colour and styling, the number of words in the anchor, whether the anchor text looks commercial, and how closely the topic of the anchor text matches the topic of the source page.
Examples of unlikely followed links may include “Terms of Service” links, banner advertisements, and links unrelated to the document.
Jeffrey A. Dean, Corin Anderson and Alexis Battle (Google), US7716225B1, Google Patents
What evidence is there that Google uses the reasonable surfer model?
This is Patent only. The patent is Google's and names a senior Google engineer as an inventor, but a patent is not proof of production use. Google's ranking systems guide confirms that link analysis systems and PageRank are used and that PageRank has evolved, without saying how links are weighted.
The US7716225 record shows the family continued in later patents (US8117209, US9305099, US10152520), which suggests Google kept the claims alive, but that is still not confirmation. The original patent's status on Google Patents is Expired, Lifetime.
How PageRank works has evolved a lot since then, and it continues to be part of our core ranking systems.
Google, A guide to Google Search ranking systems, Google Search Central
What should sites do about the reasonable surfer idea?
Act on the part that is safe whether or not the patent is in use: put links to important pages where readers will see and use them. A link in the first paragraph of a relevant article is useful to people, and under the patent's model it would carry more weight than the same link in a footer.
The falsifiable version: for each priority page, count how many of its internal links come from main content versus navigation, footer or sidebar. If almost all come from boilerplate, the page depends on the least clicked, and under this model least weighted, links on the site.
- Add contextual links from related articles to priority pages, high in the body.
- Use descriptive anchor text that matches the target page.
- Do not rely on footer link blocks to support commercial pages.
- Check click data (for example, analytics link click events) to see which links users actually follow.
Which Laurelin audit checks test for reasonable surfer issues?
The new check, Priority pages linked only from boilerplate positions, classifies each internal link by page region and flags priority pages with few or no main-content links. It measures a proxy: link placement on your pages, not the patent's model, which Google has not confirmed using.
Related checks:
- No contextual links between related pages: the direct opposite of reasonable surfer friendly linking.
- Generic anchor text: the patent lists anchor text features among link features.
- Excessive links on a page: more links means each is less likely to be followed.
- Key pages with few internal links: too few links of any placement.
- Very low content to boilerplate ratio: pages dominated by template links.
What are the key dates for reasonable surfer model?
Frequently asked questions about reasonable surfer model
Does Google use the reasonable surfer model?
Google has not confirmed it. The model is described in a Google patent, US7716225, and Google confirms that link analysis systems and PageRank are used, but not how links are weighted.
Are footer links worthless under the reasonable surfer model?
The patent describes them as less likely to be followed, so they would carry less weight, not zero. Footer links still help crawling and navigation.
Who invented the reasonable surfer model?
The patent lists Jeffrey A. Dean, Corin Anderson and Alexis Battle as inventors, with Google as assignee.