The changes, announced Thursday, apply to Yahoo search on the mobile web in the U.S., in browsers such as Safari and Chrome. Yahoo's mobile app and desktop site already provide some additional content within results.
A search on the mobile web for Barack Obama, for instance, displays information about him from Wikipedia, such as his height and birth date, as well as links to news, images and YouTube videos. In one search Thursday, the videos included some curious choices, including "Barack Obama is Illuminati."
Google already highlights a variety of content related to search queries, including news and related tweets, as well as links to other services like Maps. Microsoft's Bing does something similar.
Because Yahoo is playing catch-up, the changes might not attract many new users, but they could help it retain people who use Yahoo for mobile searches today.
In the last quarter of 2014, mobile accounted for half of Yahoo's search traffic in North America, up from 32 percent during the same period in 2013, according to research firm eMarketer.
The changes come as Yahoo works to incorporate its search service into more third-party applications. In December, it replaced Google as the default search engine for Firefox. And on Wednesday this week, CEO Marissa Mayer announced a deal with Oracle to promote Yahoo when people update the Java software on their PCs.
Zach Miners covers social networking, search and general technology news for IDG News Service. Follow Zach on Twitter at @zachminers. Zach's e-mail address is zach_miners@idg.com