Penguin - April 24, 2012
After weeks of speculation about an "Over-optimization penalty", Google finally rolled out the "Webspam Update", which was soon after dubbed "Penguin." Penguin adjusted a number of spam factors, including keyword stuffing, and impacted an estimated 3.1% of English queries.
Another step to reward high-quality sites (Google)
The Penguin Update: Google’s Webspam Algorithm Gets Official Name (SEL)
Google Penguin Update Recovery Tips & Advice (SEL)
Panda 3.5 - April 19, 2012
In the middle of a busy week for the algortihm, Google quietly rolled out a Panda data update. A mix of changes made the impact difficult to measure, but this appears to have been a fairly routine update with minimal impact.
Google Mocks Me For Missing Panda 3.5 (SER)
Parked Domain Bug - April 16, 2012
After a number of webmasters reported ranking shuffles, Google confirmed that a data error had caused some domains to be mistakenly treated as parked domains (and thereby devalued). This was not an intentional algorithm change.
Dropped In Rankings? Google’s Mistake Over Parked Domains Might Be To Blame (SEL)
Updated: Google Update April 2012? Over SEO Penalty? (SER)
March 50-Pack - April 3, 2012
Google posted another batch of update highlights, covering 50 changes in March. These included confirmation of Panda 3.4, changes to anchor-text "scoring", updates to image search, and changes to how queries with local intent are interpreted.
Search quality highlights: 50 changes for March (Google)
Google’s March Updates: Anchor Text, Image Search, Navigational Search & More (SEL)
Panda 3.4 - March 23, 2012
Google announced another Panda update, this time via Twitter as the update was rolling out. Their public statements estimated that Panda 3.4 impacted about 1.6% of search results.
Google Says Panda 3.4 Is ‘Rolling Out Now’ (SEL)
Search Quality Video - March 12, 2012
This wasn't an algorithm update, but Google published a rare peek into a search quality meeting. For anyone interested in the algorithm, the video provides a lot of context to both Google's process and their priorities. It's also a chance to see Amit Singhal in action.
Video! The search quality meeting, uncut (Google)
Panda 3.3 - February 27, 2012
Google rolled out another post-"flux" Panda update, which appeared to be relatively minor. This came just 3 days after the 1-year anniversary of Panda, an unprecedented lifespan for a named update.
Google Confirms Panda 3.3 Update (SEL)
Confirmed: Google Panda 3.3 (SER)
February 40-Pack (2) - February 27, 2012
Google published a second set of "search quality highlights" at the end of the month, claiming more than 40 changes in February. Notable changes included multiple image-search updates, multiple freshness updates (including phasing out 2 old bits of the algorithm), and a Panda update.
Search quality highlights: 40 changes for February (Google)
Venice - February 27, 2012
As part of their monthly update, Google mentioned code-name "Venice". This local update appeared to more aggressively localize organic results and more tightly integrate local search data. The exact roll-out date was unclear.
Understand and Rock the Google Venice Update (SEOmoz)
Google Venice Update – New Ranking Opportunities for Local SEO (Catalyst eMarketing)
February 17-Pack - February 3, 2012
Google released another round of "search quality highlights" (17 in all). Many related to speed, freshness, and spell-checking, but one major announcement was tighter integration of Panda into the main search index.
17 search quality highlights: January (Google)
Google’s January Search Update: Panda In The Pipelines, Fresher Results, Date Detection & More (SEL)
Ads Above The Fold - January 19, 2012
Google updated their page layout algorithms to devalue sites with too much ad-space above the "fold". It was previously suspected that a similar factor was in play in Panda. The update had no official name, although it was referenced as "Top Heavy" by some SEOs.
Page layout algorithm improvement (Google)
Pages With Too Many Ads “Above The Fold” Now Penalized By Google’s “Page Layout” Algorithm (SEL)
Panda 3.2 - January 18, 2012
Google confirmed a Panda data update, although suggested that the algorithm hadn't changed. It was unclear how this fit into the "Panda Flux" scheme of more frequent data updates.
Confirmed: Google Panda 3.2 Update (SEW)
Google Panda 3.2 Update Confirmed (SEL)
Search + Your World - January 10, 2012
Google announced a radical shift in personalization - aggressively pushing Google+ social data and user profiles into SERPs. Google also added a new, prominent toggle button to shut off personalization.
Search, plus Your World (Google)
Real-Life Examples Of How Google’s “Search Plus” Pushes Google+ Over Relevancy (SEL)
January 30-Pack - January 5, 2012
Google announced 30 changes over the previous month, including image search landing-page quality detection, more relevant site-links, more rich snippets, and related-query improvements. The line between an "algo update" and a "feature" got a bit more blurred.
30 search quality highlights - with codenames! (Google)
Google Announces “Megasitelinks,” Image Search Improvements & Better Byline Dates (SEL)
To Be Continued...