Autocomplete with math symbols
[launch codename "Blackboard", project codename "Suggest"] When we process queries to return predictions in autocomplete, we generally normalize them to match more relevant predictions in our database. This change incorporates several characters that were previously normalized: “+”, “-”, “*”, “/”, “^”, “(“, “)”, and “=”. This should make it easier to search for popular equations, for example [e = mc2] or [y = mx+b].
Improvements to handling of symbols for indexing
[launch codename "Deep Maroon"] We generally ignore punctuation symbols in queries. Based on analysis of our query stream, we’ve now started to index the following heavily used symbols: “%”, “$”, “\”, “.”, “@”, “#”, and “+”. We’ll continue to index more symbols as usage warrants.
Better scoring of news groupings
[launch codename "avenger_2"] News results on Google are organized into groups that are about the same story. We have scoring systems to determine the ordering of these groups for a given query. This subtle change slightly improves our scoring system, leading to better ranking of news clusters.
Sitelinks data refresh
[launch codename "Saralee-76"] Sitelinks (the links that appear beneath some search results and link deeper into the respective 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).
Improvements to autocomplete backends, coverage
[launch codename "sovereign", project codename "Suggest"] We’ve consolidated systems and reduced the number of backend calls required to prepare autocomplete predictions for your query. The result is more efficient CPU usage and more comprehensive prediction
Better handling of password changes
Our general approach is that when you change passwords, you’ll be signed out from your account on all machines. This change ensures that changing your password more consistently signs your account out of Search, everywhere.
Better indexing of profile pages
[launch codename "Prof-2"] This change improves the comprehensiveness of public profile pages in our index from more than two-hundred social sites.
UI refresh for News Universal
[launch codename "Cosmos Newsy", project codename "Cosmos"] We’ve refreshed the design of News Universal results by providing more results from the top cluster, unifying the UI treatment of clusters of different sizes, adding a larger font for the top article, adding larger images (from licensed sources), and adding author information.
Improvements to results for navigational queries
launch codename "IceMan5" A “navigational query” is a search where it looks like the user is looking to navigate to a particular website, such as [New York Times] or [wikipedia.org]. While these searches may seem straightforward, there are still challenges to serving the best results. For example, what if the user doesn’t actually know the right URL? What if the URL they’re searching for seems to be a parked domain (with no content)? This change improves results for this kind of search.
High-quality sites algorithm data update and freshness improvements
freshness improvements.
[launch codename “mm”, project codename "Panda"] Like many of the changes we make, aspects of our high-quality sites algorithm depend on processing that’s done offline and pushed on a periodic cycle. In the past month, we’ve pushed updated data for “Panda,” as we mentioned in a recent tweet. We’ve also made improvements to keep our database fresher overall
Live results for UEFA Champions League and KH
- We’ve added live-updating snippets in our search results for
the KHL (Russian Hockey League) and UEFA Champions League, including
scores and schedules. Now you can find live results from a variety of
sports leagues, including the NFL, NBA, NHL and others
. - Tennis search feature.
[launch codename "DoubleFault"] We’ve introduced a new search feature to provide realtime tennis scores at the top of the search results page. Try [maria sharapova] or [sony ericsson open].
More relevant image search results
Fresher image predictions in all language
SafeSearch algorithm tuning
Tweaks to handling of anchor text
Simplification to Images Universal codebase
Better application ranking and UI on mobile
Improvements to freshness in Video Universal
Fewer undesired synonyms
Better handling of queries with both navigational and local intent
and more . to see all All updates
see the below url
The main source
http://insidesearch.blogspot.com/2012/04/search-quality-highlights-50-changes.html