Google’s April Updates: Bigger & Tiered Index, Document Ranking, Sitelink Changes & More

If it’s the first Friday of the month, it must be time for Google to share its latest list of search quality updates. And, like clockwork, Google didn’t disappoint today — the company has posted a list of 53 changes that affect search results.

This list is particularly interesting because of all the upheaval happening this month, what with Panda updates 3.5 and 3.6 occurring in an eight-day span, along with the Penguin update and a Google screwup related to parked domains. Yeah, April was a crazy month for SEO folks.

As always, there’s a lot to digest and the most important items don’t always reveal themselves right away. But here’s a look at the items that caught my eye after a first read-through of Google’s blog post.

Bigger, Tiered Index

Perhaps the biggest news is that Google has increased the size of its base index — the collection of web pages and documents it can show as search results — by 15 percent.

Similarly, Google also says it’s launched a new “index tier.”

Increase base index size by 15%. [project codename “Indexing”] The base search index is our main index for serving search results and every query that comes into Google is matched against this index. This change increases the number of documents served by that index by 15%. *Note: We’re constantly tuning the size of our different indexes and changes may not always appear in these blog posts.

New index tier. [launch codename “cantina”, project codename “Indexing”] We keep our index in “tiers” where different documents are indexed at different rates depending on how relevant they are likely to be to users. This month we introduced an additional indexing tier to support continued comprehensiveness in search results.

That sounds almost like Google’s old “supplemental index” system that launched in 2003, and it may be tempting to say the supplemental index has returned, or something along those lines. But, as far as I recall, Google never said the supplemental index was going away; it said they’d stop using the “Supplemental Results” label on search results that came from it.

SEO & Ranking Updates

Google has also announced numerous updates that relate to how documents are ranked, updates that sound like they’re at least related to — if not part of — the larger Panda and Penguin updates that are already well known.

Improvements to how search terms are scored in ranking. [launch codename “Bi02sw41”] One of the most fundamental signals used in search is whether and how your search terms appear on the pages you’re searching. This change improves the way those terms are scored.

Keyword stuffing classifier improvement. [project codename “Spam”] We have classifiers designed to detect when a website is keyword stuffing. This change made the keyword stuffing classifier better.

More authoritative results. We’ve tweaked a signal we use to surface more authoritative content.

More domain diversity. [launch codename “Horde”, project codename “Domain Crowding”] Sometimes search returns too many results from the same domain. This change helps surface content from a more diverse set of domains.

If I were to guess, I’d think that the first two items above could be related to “spun” content — one of the practices that Google likely considers to be a hallmark of low-quality content. But that’s just a guess on my part.

The last two items — authoritative results and domain diversity — almost sound contradictory. At least to me. On a Friday afternoon during a long week with international travel.

Sitelinks Updates

There are several changes related to Google’s sitelinks and “megasitelinks” — the additional links that show up below a top-ranking result for some queries.

If you spend time trying to optimize for sitelinks (and if you have an authoritative site, it’s probably a good idea to be doing that), these changes are worth reading closely. Here are those changes, word-for-word from Google’s post:

“Sub-sitelinks” in expanded sitelinks. [launch codename “thanksgiving”] This improvement digs deeper into megasitelinks by showing sub-sitelinks instead of the normal snippet.

Better ranking of expanded sitelinks. [project codename “Megasitelinks”] This change improves the ranking of megasitelinks by providing a minimum score for the sitelink based on a score for the same URL used in general ranking.

Sitelinks data refresh. [launch codename “Saralee-76”] Sitelinks (the links that appear beneath some search results and link deeper into the site) are generated in part by an offline process that analyzes site structure and other data to determine the most relevant links to show users. We’ve recently updated the data through our offline process. These updates happen frequently (on the order of weeks).

Less snippet duplication in expanded sitelinks. [project codename “Megasitelinks”] We’ve adopted a new technique to reduce duplication in the snippets of expanded sitelinks.

The first item seems to be saying that sub-sitelinks may show up instead of a text snippet, which I think means that some search results could have two layers of sitelinks — megasitelinks below the main result, and then sub-sitelinks below one of the megasitelinks. I’ve not seen anything like that yet.

Local-related Changes

There are a couple changes related to local/geo searches and search results.

Improvements to local navigational searches. [launch codename “onebar-l”] For searches that include location terms, e.g. [dunston mint seattle] or [Vaso Azzurro Restaurant 94043], we are more likely to rank the local navigational homepages in the top position, even in cases where the navigational page does not mention the location.

Country identification for webpages. [launch codename “sudoku”] Location is an important signal we use to surface content more relevant to a particular country. For a while we’ve had systems designed to detect when a website, subdomain, or directory is relevant to a set of countries. This change extends the granularity of those systems to the page level for sites that host user generated content, meaning that some pages on a particular site can be considered relevant to France, while others might be considered relevant to Spain.

In the first item, Google seems to be saying that it’s able to able to identify the correct local result for specific navigational searches — such as a search for a specific local restaurant — even if the site/page is poorly optimized for local search.

It’s reminiscent of the “Venice” update earlier this year which involved Google launching ways to better correlate web pages/documents to their locations.

Miscellaneous Updates

In addition to the items I’ve highlighted above, read through Google’s post for these other items that caught my eye:

• A change that should reduce amount of paginated results showing on a search results page.
• Two changes related to snippets, including one which promises to show more text from the beginning of pages.
• Three changes related to freshness — fresh results and freshness signals, and one that ignores fresh content if it’s deemed low quality. (There’s also an Autocomplete change designed to reduce the visibility of low-quality results.)
• A change that Google says will help it show more informative/concise titles in its search results. (For what it’s worth, just about every SEO that I know wishes Google wouldn’t change titles at all.)
• Improvements in how Google uses previous search activity to determine your intent as you continue to search.

That’s a lot to digest and something else may have caught your attention as being important. The comments are open, so let us know what stands out for you as you look through Google’s April search changes.