We’ve all been waiting for it, and now it’s here: Google’s monthly list of algorithm changes for May. This time, it’s 39 changes (less than last month).

Of particular note, Google says it made a couple of adjustments to Penguin:
Improvements to Penguin. [launch codename "twref2", project codename "Page Quality"] This month we rolled out a couple minor tweaks to improve signals and refresh the data used by the penguin algorithm.
Also noteworthy:
Better application of inorganic backlinks signals. [launch codename "improv-fix", project codename "Page Quality"] We have algorithms in place designed to detect a variety of link schemes, a common spam technique. This change ensures we’re using those signals appropriately in the rest of our ranking.
Of course, Google also made more adjustments to freshness.
We’ll be digging into these much more, but for now, here’s the list in its entirety:
  • Deeper detection of hacked pages. [launch codename "GPGB", project codename "Page Quality"] For some time now Google has been detecting defaced content on hacked pages and presenting a notice on search results reading, “This site may be compromised.” In the past, this algorithm has focused exclusively on homepages, but now we’ve noticed hacking incidents are growing more common on deeper pages on particular sites, so we’re expanding to these deeper pages.
  • Autocomplete predictions used as refinements. [launch codename "Alaska", project codename “Refinements”] When a user types a search she’ll see a number of predictions beneath the search box. After she hits “Enter”, the results page may also include related searches or “refinements”. With this change, we’re beginning to include some especially useful predictions as “Related searches” on the results page.
  • More predictions for Japanese users. [project codename "Autocomplete"] Our usability testing suggests that Japanese users prefer more autocomplete predictions than users in other locales. Because of this, we’ve expanded the number or predictions shown in Japan to as many as eight (when Instant is on).
  • Improvements to autocomplete on Mobile. [launch codename "Lookahead", project codename "Mobile"] We made an improvement to make predictions work faster on mobile networks through more aggressive caching.
  • Fewer arbitrary predictions. [launch codename "Axis5", project codename "Autocomplete"] This launch makes it less likely you’ll see low-quality predictions in autocomplete.
  • Improved IME in autocomplete. [launch codename "ime9", project codename "Translation and Internationalization"] This change improves handling of input method editors (IMEs) in autocomplete, including support for caps lock and better handling of inputs based on user language.
  • New segmenters for Asian languages. [launch codename "BeautifulMind"] Speech segmentation is about finding the boundaries between words or parts of words. We updated the segmenters for three asian languages: Chinese, Japanese, and Korean, to better understand the meaning of text in these languages. We’ll continue to update and improve our algorithm for segmentation.
  • Scoring and infrastructure improvements for Google Books pages in Universal Search.[launch codename “Utgo”, project codename “Indexing”] This launch transitions the billions of pages of scanned books to a unified serving and scoring infrastructure with web search. This is an efficiency, comprehensiveness and quality change that provides significant savings in CPU usage while improving the quality of search results.
  • Unified Soccer feature. [project codename "Answers"] This change unifies the soccer search feature experience across leagues in Spain, England, Germany and Italy, providing scores and scheduling information right on the search result page.
  • Improvements to NBA search feature. [project codename "Answers"] This launch makes it so we’ll more often return relevant NBA scores and information right at the top of your search results. Try searching for [nba playoffs] or [heat games].
  • New Golf search feature. [project codename "Answers"] This change introduces a new search feature for the Professional Golf Association (PGA) and PGA Tour, including information about tour matches and golfers. Try searching for [tiger woods] or [2012 pga schedule].
  • Improvements to ranking for news results. [project codename "News"] This change improves signals we use to rank news content in our main search results. In particular, this change helps you discover news content more quickly than before.
  • Better application of inorganic backlinks signals. [launch codename "improv-fix", project codename "Page Quality"] We have algorithms in place designed to detect a variety of link schemes, a common spam technique. This change ensures we’re using those signals appropriately in the rest of our ranking.
  • Improvements to Penguin. [launch codename "twref2", project codename "Page Quality"] This month we rolled out a couple minor tweaks to improve signals and refresh the data used by the penguin algorithm.
  • Trigger alt title when HTML title is truncated. [launch codename "tomwaits", project codename "Snippets"] We have algorithms designed to present the best possible result titles. This change will show a more succinct title for results where the current title is so long that it gets truncated. We’ll only do this when the new, shorter title is just as accurate as the old one.
  • Efficiency improvements in alternative title generation. [launch codename "TopOfTheRock", project codename "Snippets"] With this change we’ve improved the efficiency of title generation systems, leading to significant savings in cpu usage and a more focused set of titles actually shown in search results.
  • Better demotion of boilerplate anchors in alternate title generation. [launch codename "otisredding", project codename "Snippets"] When presenting titles in search results, we want to avoid boilerplate copy that doesn’t describe the page accurately, such as “Go Back.” This change helps improve titles by avoiding these less useful bits of text.
  • Internationalizing music rich snippets. [launch codename "the kids are disco dancing", project codename "Snippets"] Music rich snippets enable webmasters to mark up their pages so users can more easily discover pages in the search results where you can listen to or preview songs. The feature launched originally on google.com, but this month we enabled music rich snippets for the rest of the world.
  • Music rich snippets on mobile. [project codename "Snippets"] With this change we’ve turned on music rich snippets for mobile devices, making it easier for users to find songs and albums when they’re on the go.
  • Improvement to SafeSearch goes international. [launch codename "GentleWorld", project codename "SafeSearch"] This change internationalizes an algorithm designed to handle results on the borderline between adult and general content.
  • Simplification of term-scoring algorithms. [launch codename "ROLL", project codename "Query Understanding"] This change simplifies some of our code at a minimal cost in quality. This is part of a larger effort to improve code readability.
  • Fading results to white for Google Instant. [project codename "Google Instant"] We made a minor user experience improvement to Google Instant. With this change, we introduced a subtle fade animation when going from a page with results to a page without.
  • Better detection of major new events. [project codename "Freshness"] This change helps ensure that Google can return fresh web results in realtime seconds after a major event occurs.
  • Smoother ranking functions for freshness. [launch codename "flsp", project codename "Freshness"] This change replaces a number of thresholds used for identifying fresh documents with more continuous functions.
  • Better detection of searches looking for fresh content. [launch codename "Pineapples", project codename "Freshness"] This change introduces a brand new classifier to help detect searches that are likely looking for fresh content.
  • Freshness algorithm simplifications. [launch codename “febofu", project codename "Freshness"] This month we rolled out a simplification to our freshness algorithms, which will make it easier to understand bugs and tune signals.
  • Updates to +Pages in right-hand panel. [project codename “Social Search”] We improved our signals for identifying relevant +Pages to show in the right-hand panel.
  • Performance optimizations in our ranking algorithm. [launch codename "DropSmallCFeature"] This launch significantly improves the efficiency of our scoring infrastructure with minimal impact on the quality of our results.
  • Simpler logic for serving results from diverse domains. [launch codename "hc1", project codename "Other Ranking Components"] We have algorithms to help return a diverse set of domains when relevant to the user query. This change simplifies the logic behind those algorithms.
  • Precise location option on tablet. [project codename “Mobile”] For a while you’ve had the option to choose to get personalized search results relevant to your more precise location on mobile. This month we expanded that choice to tablet. You’ll see the link at the bottom of the homepage and a button above local search results.
  • Improvements to local search on tablet. [project codename “Mobile”] Similar to thechanges we released on mobile this month, we also improved local search on tablet as well. Now you can more easily expand a local result to see more details about the place. After tapping the reviews link in local results, you’ll find details such as a map, reviews, menu links, reservation links, open hours and more.
  • Internationalization of “recent” search feature on mobile. [project codename "Mobile"] This month we expanded the “recent” search feature on mobile to new languages and regions.