Passage ranking is an AI system Google uses to identify individual sections, called passages, of a web page to better understand how relevant the page is to a search. Google announced it on October 15, 2020.
At a glance
- Type
- AI system that assesses individual passages of a page
- Started
- October 15, 2020 (announced)
- Affects
- Google expected an improvement for 7% of queries
- Completed
- ongoing (current system)
- Confirmed by
- yes
- Status
- listed as a current system in the ranking systems guide
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What does passage ranking do?
At its Search On event in 2020, Google said that understanding passages in addition to the overall page helps find specific information buried in a longer page. Google expected the change to improve 7 percent of search queries across all languages as it rolled out globally. The figure counts search queries.
The ranking systems guide lists passage ranking as an active system. Google describes it as a way to judge a page’s relevance. In the sources checked, Google does not say that passages are indexed as separate documents, although the term “passage indexing” is common.
- Google announces the completion of Caffeine, its new web indexing system. Google says it delivers 50 percent fresher results than the previous index.Source: googleblog.blogspot.com
- Google announces a ranking change against low-quality and copied content that noticeably affects 11.8% of queries. Google later refers to the system by its nickname “Panda”.Source: googleblog.blogspot.com
- Google improves how it decides when to favour recent results. According to Google the change affects roughly 35 percent of searches and builds on Caffeine.Source: googleblog.blogspot.com
- Google launches a change that looks at page layout. Pages with little content and many ads above the fold may rank lower.Source: developers.google.com
- Google announces a change against webspam, later nicknamed “Penguin”. It affects about 3.1% of English queries and roughly 3% of German queries.Source: developers.google.com
- Hummingbird, which Google describes as a major improvement to its overall ranking systems.Source: developers.google.com
- Panda becomes part of the core ranking systems. Google now lists it among its retired systems.Source: developers.google.com
- Google launches RankBrain, the first deep learning system used in Search. It relates the words in a query to real-world concepts.Source: blog.google
- Google starts rolling out the mobile-friendly update, boosting mobile-friendly pages in mobile search results. The industry unofficially calls it “Mobilegeddon”.Source: developers.google.com
- Penguin becomes part of the core algorithm and now works in real time. Before that, the list of affected sites was only refreshed periodically.Source: developers.google.com
- Google introduces neural matching. The system helps relate queries to pages through underlying concepts.Source: blog.google
- Launch of SpamBrain, Google’s AI-based spam prevention system. Google says it identified nearly six times more spam sites in 2021 than in 2020.Source: developers.google.com
- Google applies BERT to ranking and featured snippets. At launch it affects about one in ten English searches in the US.Source: blog.google
- Google presents passage ranking, which can assess individual passages of a page for a query. Google expects it to improve 7 percent of queries.Source: blog.google
- First product reviews update. It rewards in-depth product reviews and initially covers English-language reviews only.Source: developers.google.com
- Google introduces MUM, a model trained across 75 languages. Google calls it 1,000 times more powerful than BERT.Source: blog.google
- First link spam update. It aims to identify and nullify link spam across multiple languages and rolls out over two weeks.Source: developers.google.com
- With the helpful content update, Google aims to show more original, helpful content written for people.Source: status.search.google.com
- December 2022 helpful content update. Google says it improves the classifier and works globally in all languages.Source: status.search.google.com
- The product reviews update becomes the reviews update. Google says it now covers reviews of products, services and other things.Source: status.search.google.com
- September 2023 helpful content update. Google says it improves the classifier again.Source: status.search.google.com
- November 2023 reviews update. As the reviews system is now improved at a regular pace, Google no longer posts future updates on the Status Dashboard.Source: status.search.google.com
- The helpful content system becomes part of the core ranking systems. Google now lists it among its retired systems.Source: developers.google.com
- Three new spam policies against expired domain abuse, scaled content abuse and site reputation abuse. The March 2024 spam update launches the same day.Source: developers.google.com
- The site reputation abuse policy takes effect. Google had given site owners time to prepare since March.Source: developers.google.com
- In the US antitrust case against Google, the court describes Navboost as a signal that memorises which documents users click for a query. This is a court document, not a Google publication.Source: storage.courtlistener.com
- Google tightens the site reputation abuse policy. First-party involvement does not change the assessment when third-party content exploits the host site’s ranking signals.Source: developers.google.com
A selection, not a complete list. Core and spam updates since November 2021 have their own timeline. Names such as Florida (2003), Pigeon (2014), Possum (2016), Fred (2017) and Medic (2018), as well as Payday Loan and EMD, come from the SEO industry. Their dates rest only on trade press reports and posts by Google employees on X; Google has not published a dated page about them. Last checked: .
Example
A long guide about home renovation contains one short section on removing old wallpaper. A search for how to remove wallpaper from plaster may show the guide because that section matches, even if the page as a whole is about renovation in general (constructed example).
FAQ
Do pages need to be split into separate URLs? Google’s announcement describes passage understanding within a page. It does not call for splitting pages.
Sources
- Ranking systems guide – Google Search Centraldevelopers.google.com
- How AI is powering a more helpful Google (Search On) – Google Blog, 2020-10-15blog.google
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