1) Panda (26 updates) – Launched Feb. 23, 2011
If you’re focused on adding high-quality content to your site, Panda is your friend. Panda rewarded high-quality sites by suppressing sites that abused content — a process that affected 12% of searches. Panda affected “content farms” (sites that generated massive amounts of original, low-quality content), sites with thin content (automatically generated, scraped content or doorway pages) and pages with poor ad-to-content ratios (excessive number of ads, especially above the fold). Most notably, Overstock.com and JC Penney were penalized by Google for these tactics. There have been 25 tracked subsequent updates, the most recent being Panda 4.0 in May (which affected 7.5% of all searches).
2) Penguin(5 updates) – Launched April 24, 2012
Penguin targeted sites using SEO techniques that violated Google’s quality guidelines. This included keyword stuffing (overloading of keywords or phone numbers), link schemes (buying or selling links, unnatural links and forum comments with signature links) and other methods of gaming the system to improve search rankings. This change only affected 3% of queries, but it significantly impacted sites gaining an unfair SEO advantage. Four subsequent Penguin updates have had a profound impact — all sites should now be reviewed via regular Link Audits to rule out the presence of spam links. Penguin 3.0 is rumored to reward sites that have done the hard work of disavowing nefarious links.
3) Knowledge Graph (2 updates) – Launched May 16, 2012
“Things, not strings,” is how Google describes the Knowledge Graph, an instantly returned element that gets strong prominence on the search results page. The premise is that words represent things and search results should provide better information than simple links to pages. This is typically a picture/map, with description and links at the top right or even top center of search results (mobile search or sports scores/schedules, stock ticker/results on desktop). The second update to Knowledge Graph (KG) increased KG results by 50%, with a quarter of all searches now including some kind of KG content. Google pulls this content from numerous sources, including Google Plus, so it’s good to have a completed G+ account profile that includes recent posts and reviews.
4) Hummingbird – Launched Aug. 20, 2013
Hummingbird is a relatively new search algorithm, the biggest change since the Caffeine update in June of 2010. Google retained the best parts of its previous algorithm while adding in new elements specifically tailored to the present needs of search. One of these areas is “conversational search,” which includes searches phrased as questions (and spoken searches) and incorporates previous queries and natural language processing. The idea here is that facts and pages can be connected in ways beyond explicit matches of keywords.
5) Pigeon– Launched July 24, 2014
Google’s most recent update had a major impact on local search results. Following Google’s current less-explicit approach to updates, this is the first major update to be named by the search community, not Google. This change ties local results more closely to traditional search ranking signals, improves distance and ranking parameters, and results in more three-packs (three local results) and fewer seven-packs. This change also favors directory sites and puts more emphasis on local businesses than local brands.
There is rarely a dull moment in the world of Google’s algorithm. A big change has either just happened or is on the way. Understanding the major implications is critical to search performance, but the bottom line is to know Google’s rules and to play by them.