Google Blog Search and Technorati are two blog search engines I use regularly, hence I should be able to make a comparison between them by evaluating the main features. If you don’t know the differences between a blog search engine and a web search engine click here.

Technorati is both a social networking system and a search engine for blogs, but search results are ordered only by freshness and you have not the possibility to choose another way to sort them. In my opinion this is the weakness of Technorati. Indeed I use Technorati just to look for news in the blogosphere, that’s that.

Instead, by using Google Blog Search you can sort search results both by date and by relevance (default setting). Google experience in searching brings a better accuracy in result, but it’s not so unusual to obtain search results which are not blogs. And this is not good for a blog search engine! Maybe this is due by the fact that Google Blog Search is still a beta version and only recently has launched an own Pinging Service.

When in mid December 2006 Google Blog Search surpassed Technorati in market share of visits (although TechCruch didn’t agree with the stats by hitwise) I was not surprised. It has been enough to place a link to Blog Search on the Google News home page to rocket its traffic.

I think Google Blog Search reaches mainly people that have never used a blog search engine before. Moreover most people could not like a blog search engine that lists just recent posts, such as Technorati. This might be good for who’s looking for (technology) news, but not for the remaining people.

Clusty is a Meta Web Search Engine offered by Vivísimo [Search Done Right]. Vivísimo’s technology has received a tremendous amount of industry recognition and Vivísimo Velocity has recently won the ‘Best Enterprise Search Solution’ in InfoWorld’s 2007 Technology of the Year Awards Two Years in a Row and has been chosen by U.S. News and World Report to improve and optimize search engine resources for its editorial staff. On the other hand Firstgov.gov, the U.S. government’s official web portal uses Clusty (combined with MSN Search) as Firstgov search engine.

I have heard about Vivísimo and Clusty during a university lesson about Information Retrieval and Machine Learning.

They used a mathematical algorithm and deep linguistic knowledge to find relationships between search terms and bring them to light.

But I want to focus on Clusty. What makes Clusty unique?

Clusty is a whole new way to search the web.

Clusty queries several top search engines, combines the results, and generates an ordered list based on comparative ranking. This “metasearch” approach helps raise the best results to the top and push search engine spam to the bottom.

But what really makes Clusty unique is what happens after you search. Instead of delivering millions of search results in one long list, our search engine groups similar results together into clusters. Clusters help you see your search results by topic so you can hone in on exactly what you’re looking for or discover unexpected relationships between items. When was the last time you went to the third or fourth page of the search results? Rather than scrolling through page after page, the clusters help you find results you may have missed or that were buried deep in the ranked list.

Here is how Clusty results appear. The query is green apple.

Automated grouping of search results by topic is called Search Clustering. It allows the user to further refine the results by clicking on cluster or sub-cluster. «Are you looking for a kind of fruit or for one of the Greenpeace campaigns against Apple? Or for something else?». But there are not only clusters! Clusty Web Search allows you to see which source or sources the results are coming from (Ask, Gigablast, MSN, Wikipedia,…) and select what you prefer. You can do the same thing with the URLs.

Google has recently added clustering to the Google Search Appliance, a box that indexes documents from a company’s intranet and web sites.

It will be interesting to see if Google decides to add clustering to the web search. Other search engines that have this features (like Clusty) don’t have extraordinary results, but may help you view the big picture and guide you in refining your query.

I think clustering could help people to start obtaining information from web search engines, and not just webpages.

Clusty Search Engine is available also for News, Images, Wikipedia, Blogs, Jobs, Shopping,… For more details I refer to this Overview of Clustering and Clusty Search Engine on Read/Write Web.

Tell me what you think about Clusty in a comment.