Yahoo! army of 500 million takes on Google

Little irks Terry Semel, boss of the internet giant Yahoo! more than to hear the name of his arch rival used as a verb. Because while tens of millions of people go googling for information on the web every day, a yahoo is still just a crude person.

Now, an assault on Google's dominance as a gateway to the internet, has been planned by Yahoo!, who want to tap into the knowledge of its half a billion users around the world.

Yahoo! says it has created a more sophisticated search engine than Google, one that will change the way people surf the web. It could also crack some of the most difficult technical challenges that prevent the internet becoming a real - and anarchic - alternative to television as a source of entertainment.

Mr Semel unveiled Yahoo!'s new vision of "social search" to Wall Street pundits eager to see how the company can claw back the ground it has lost to Google. Five years ago, before Google's wildfire growth had really begun, Yahoo bestrode the internet as the most widely used "portal" or gateway. The company believes it will be able to win back that top spot by making it easier for users to find not just individual websites, but answers to specific questions. He said: "Half the searches on the web involve three words or more. People are becoming more specific, and drilling down to find what they want."

In essence, what Yahoo! plans is a search engine that learns - and a community of 500 million users who have an interest in teaching it.

Yahoo! will begin asking its users to label video clips to allow its computers to accurately catalogue and search content that otherwise might go unrecognised. The mushrooming numbers of user-generated comedy sketches - which have turned laddish sites such as YouTube into a web phenomenon - are starting to make television executives nervous for the future of their centrally-cast comedy shows.

The new search service will also tap into the 6 million discussion groups used by 90 million Yahoo! subscribers, allowing access to their thoughts on everything from relationships to cars. It will also dovetail with Yahoo! Answers, whose users share queries and answers on subjects from how to fix an old camera to what dog to get for a given size of Manhattan apartment. To encourage participation and reward quality and relevant answers, Yahoo! Answers has a system of points where users who are regularly voted as providing the "best answer" can build a reputation within the community as a trusted source for information.

Google has begun testing a similar concept called Google Co-Op, whose users help to rank sources of information and also hand over information about their favourite sites. But Google is a long way behind Yahoo! in creating an army of loyal users for its Gmail and chat services. It is also nervous that accumulating data on users will be seen as an invasion of privacy and a betrayal of the hippy-ish roots exemplified by its corporate slogan "Do No Evil".

Yahoo! has no such qualms. More information on its users will enable the company to target users with more personalised adverts. Improving the experience for users also improves the service to advertisers, Mr Semel said. His investors and financial pundits lapped it up.