Google Inc. and Yahoo Inc. are redefining the online news experience, but in diverging ways that underscore the evolving identities of the search giants.

Last week, Yahoo unveiled the Upshot, a blog created by the Sunnyvale portal's growing staff of editors and reporters, who will use search and other user data to help determine what they'll cover and how.

That announcement followed the introduction of a new version of Google News, which allows users to customize the content they see, but leaves the writing and editing to others.

Yahoo's new blog highlights its transformation into a 21st century media company, a destination that uses a combination of technology and humans to find or create the content people want.

Meanwhile, Google continues to demonstrate an unflinching faith in the ability of increasingly sophisticated search technology to evaluate and point to the most relevant content from across the Internet.

"It reaffirms the fact that Yahoo is trying to be a media company, have its own content and keep people at Yahoo, whereas Google is the opposite," said Danny Sullivan, editor in chief of Search Engine Land, a site covering the industry. "They want to push you away from Google to other publishers."

In the process, both are providing instant access to a growing array of headlines while at the same time letting users personalize, filter and, at least with Yahoo, even influence what they read.

Yahoo expands original content

Yahoo is already the most popular news site, with nearly 41 million unique visitors in 2009, according to Nielsen. It licenses content from hundreds of newspapers, wire services and other sources, and supplements those stories with links to stories that its editors and search algorithms pull in from around the Web.

The Upshot will augment rather than replace what Yahoo has built to date, said Mark Walker, vice president of news and information.

"Clearly we've gone as far as one might expect to go with aggregation," he said. "So the idea is to have a right-sized layer of original content to go on top of that, produced by Yahoo for Yahoo with some idea of Yahoo's audience."

Yahoo has been producing well-regarded sports blogs for some time, so what's really new here is that the company is wading deeper into original content and tapping into its user behavior data to make editorial decisions.

The latter model has been championed by companies like Demand Media, AOL's Seed division and Associated Content, which Yahoo agreed to acquire earlier this year for what was reported to be at least $90 million. Known derisively as web farms, the businesses use armies of freelancers to crank out content based largely on popular search terms.

Some journalists and observers cringe over both the use of queries to determine news value - the top three topics on Yahoo at press time were "Jennifer Aniston," "Don Johnson" and "Roman coins" - and what are reportedly meagerly paid freelancers to produce an increasingly large portion of the Web's news. They complain the content is rushed out, cobbled together from sources that did deeper reporting, and designed to trigger search engines rather than human interest.

Walker declined to discuss plans for Associated Content in depth, but stressed that the Upshot's full-time writers and editors will merely take advantage of user data as one more input in the editorial process, alongside traditional tips, sources and reporting.

"That is only meant to advance the functioning of journalism," he said, adding that aggregation from third parties will continue to supply the balance of news to the site and that quality will determine the rankings. "We'll never benefit by running an inferior story from our own source."

Allen Weiner, an analyst at Gartner Research and a former journalist - whose roles included manager of new media for The Chronicle - agreed.

"Giving editors the tools to understand what people are interested in, I think, is extremely powerful," he said.

But Yahoo's expanded breadth of original material from the Upshot and Associated Content could create new challenges too, including content partners who could see the moves as new competition, Weiner said.

Google's tech makes it personal

Google News ranks sixth among online news sites, with just under 15 million unique visitors, behind MSNBC, AOL News, CNN and the New York Times, according to Nielsen.

Started in 2002, the service flipped the traditional way that people consumed news on its head. Instead of delivering the day's stories from pre-selected sources, as a newspaper or even many online aggregators do, it offers headlines from a number of outlets and allows people to choose which ones to read.

At the end of last month, the Mountain View company redesigned the site, allowing users to pick the subjects and sources they're most interested in, as well as local news and weather for areas they choose. Google also introduced tools that let readers share stories over its Buzz and Reader services, as well as Facebook and Twitter.

Humans write the Google algorithms that pull in the news, but beyond that, the computers decide which headlines show up where. The technology looks for signals to determine the credibility of sources and interest in stories, including the number of fresh articles a site produces, the way publishers play their stories, how frequently an article is reposted and how readily users click on the links.

"It's a different business model," said Josh Cohen, senior product manager for Google News. Yahoo is "moving more in the direction of content creation and generation. We're still coming at this from a discovery standpoint."

He says it ties into Google's mission statement - to organize the world's information and make it universally accessible. Aside from a few small-scale projects, including a YouTube interview with then-Sen. Barack Obama, Google isn't creating content.

It's an important distinction for publishers. While Yahoo gets most of the news traffic, Google receives the lion's share of complaints from content creators over the use of their headlines. That's arguably because while Google News itself isn't a huge money maker, the company claims an estimated 30 percent of all online advertising spending. Meanwhile, the dramatic shift in ad dollars to the Web has left many traditional publishers struggling to survive.

Media giants like News Corp. and the Associated Press have assailed Google's efforts to provide news, and any hint the company plans to compete directly would be fuel on the fire.

"If Google had announced, 'We have this new blog and we're going to have some journalists working for us,' there would be pitchforks," Sullivan said.

Google continually stresses that it's a friend to news sites, sending them huge volumes of traffic and developing tools to help the industry make more money online. That includes the development of a one-click payment system for content, which reports suggest could be unveiled soon.

Cohen said the average Google News user clicks on at least one story per visit, directing about a billion people to news sites each month. Another 3 billion arrive via the Google home page and search engine.

"We definitely see ourselves as a starting point, not a destination," he said.