How do search engines decide how to rank news-related results?
It's a top-of-mind question since President Donald Trump accused Google on Tuesday of prioritizing negative coverage from left-leaning outlets, an indictment that appeared to be based on an unscientific report by a conservative news site. Google also denied it uses political bias in search results.
Google is by far the most popular search engine in the United States, with 86 percent market share, according to StatCounter. But there is an alternative: Microsoft's Bing.
Although both search engines use algorithms that are largely a black box to outsiders, their own descriptions of how they rank news are largely the same. Both determine which stories to feature based on their judgement of a source's relevance and authority, though Bing also weighs "readability" and "originality" into its rankings.
Here's how the two search engines determine what news to display.
When Google's algorithm chooses which top news stories to display, it takes into account freshness, relevancy and authoritativeness, according to The Associated Press. It chooses which stories have "authority" based on judgments about the site publishing them, guided by fine-tuning from a group of 10,000-plus employees known as search quality raters who judge authority based on recommendations from professional societies, as well as factors like whether the outlet has won Pulitzer Prizes, clearly labels advertising or may intentionally deceive users.
When Bing's algorithm chooses which stories to display, it takes into consideration whether the source of the news ranks well for newsworthiness, originality, authority, relevance and readability. Bing also has search quality raters, and defines "authority" as outlets that "identify sources, authors and attribution of all content." Readability includes sites that have correct grammar and spelling and where advertising doesn't interfere with the user experience. It defines "originality" as sites with unique facts or points of view.
Bing also has a feature called "Spotlight" to provide overviews of certain news topics by showing a timeline of events from "various perspectives" (an example is shown below for the query "NFL anthem kneeling"). Google's has similar features in its revamped News app, though it doesn't include them in its main search interface.
Here's a look at how both Google and Bing ranked news on Wednesday morning (click an image to enlarge).
Donald Trump
Bing
John McCain
Bing
Climate change
Bing
NFL anthem kneeling
Bing
