Yahoo Inc. on Thursday released in beta an online service that lets registered users post and answer questions, a move that adds a human element to Web searching.

The Sunnyvale, Calif., portal said Yahoo Answers complements its standard search engine by letting people ask straightforward questions and receive answers based on the collective knowledge of other Yahoo subscribers.

The service addresses the need for answers to everyday question that can't be easily handled through keyword searches, the company said. Questions and answers posted through the new service are archived and categorized by topic to make them searchable.

Users can set up RSS feeds either through their My Yahoo personal portal or some other newsreader, in order to receive the latest questions and answers on selected topics. Answers to individual questions are posted on the site, and can also be delivered through email.

"At Yahoo, we are huge believers in the power of community," Ofer Shaked, director of engineering at Yahoo Search, said in a statement.

Users of the service can also vote on the best answer to their question, which, over time, is expected to boost the reputation of people who deliver the most valuable information on specific topics, Yahoo said.

While not meant to replace the quick answers people get through traditional search engines, the new service appears to follow the strategy among portals to offer services that keep visitors on the site longer, and keeps them coming back, thereby increasing their exposure to advertising. An effective means of accomplishing this goal is to build social networks in which people share information.

Yahoo is not the first to offer a search service based on human interaction. Rival Google offers a fee-based service called Google Answers, in which users tell researchers how much they're willing to pay for answers. Queries and research are posted on the Google Answers Web site, so registered users can also have access to the information and contribute their own insights.