"They needed to freshen things up," said Brian Blau, research director of consumer technologies for Gartner Inc. "This should bring a lot of cooler things" into the News Feed.Although Zuckerberg didn't say it, the overhaul also appears to be aimed at carving out more space to show larger and more compelling ads within the News Feed as Facebook seeks to boost its revenue and stock price. Previous tweaks to the News Feed have triggered howls of protest among Facebook's users. Hoping to minimize the grousing this time around, Facebook intends to roll out the changes in phases. It will probably be at least six months before everyone who accesses Facebook on a personal computer sees the revamped News Feed, the company said. New mobile applications featuring the changes should be released within that time frame too. The transition is likely to be completed before Facebook celebrates its 10th birthday next February. The facelift is likely to be more jarring for those who only visit Facebook on a PC because it incorporates some features already deployed in the social network's mobile applications for smartphones and tablet computers. The new features will enable users to choose to see streams of content that may feature nothing but photos or posts from their closest friends, family members or favorite businesses. Or they can just peruse content about music, or sports, as if they were grabbing a section of a newspaper. Other newspaper-like changes will include lists of events that users' social circles have flagged for the upcoming weekend and other summaries meant to resemble a table of contents. Facebook still intends to rely on algorithms to select some material to feature on the main part of the News Feed, much like newspaper editors determine what goes on the front page. The additional space being devoted to photos and video is an acknowledgement how dramatically the composition of Facebook's content has changed during the past 16 months. About 50 percent of the posts on News Feed now include a photo or video now, up from 25 percent in November 2011, according to Facebook's data.