Was former President Barack Obama's birth certificate faked so he could run for office? It depends on how you ask Google.

The search engine giant last week expanded a test fact-checking program worldwide in a bid to help stop the spread of misinformation after it faced criticism for returning fake and offensive information in its popular search queries.

USA TODAY tested the feature out, asking Google a range of questions previously proven false — and some known to be true.

The result: Whether an answer surfaced what Google calls a "fact-check snippet" depended on how you phrased the question and whether the topic had been fact-checked by an organization taking part in Google's program. The snippets aren't tags on specific stories but rather on search words or phrases that appear in the list of results.

Search "Obama Kenyan citizen" and a fact check snippet pops up from Snopes.com, detailing reasons why a purported Kenyan birth certificate for Obama was a fake.

Search "Obama birth certificate fake," however, and no snippet turns up. Instead, the first link is a story from WorldNetDaily, a site run by leading birther proponent Joseph Farah, which says that Obama's Hawaiian birth certificate was faked.

The responses highlight the difficulties the world's most popular search engine faces as it works to offer users more authoritative and credible information after being critiqued for returning fake and offensive information items in response to some queries.

Google had been running a limited test fact check program in the United States and the United Kingdom for articles on news.google.com since October. The new roll-out applies to all searches worldwide — not just news — in all languages it supports. The inclusion of a fact-check topic won't affect the ranking of search results.

The information in the fact check tags comes from third-party fact-checking organizations. In the United States so far those include PolitiFact.org, FactCheck.org, Snopes.com, the Washington Post, the New York Times and GossipCop.com. Internationally there are between 50 and 100 groups offering tags, Google said. The fact checking doesn't just cover political stories, but a broader swathe, including science and health.

The search terms that trigger fact check snippets depend on whether a given topic has been the subject of a fact check and what words and phrases were tagged.

While it's unclear if the results might sway those committed to a specific point of view, they give a sense of the power Google has to tailor search results for a specific purpose.

The Mountain View, Calif.-based search giant's move comes a month after Facebook began adding a "disputed" warning tag to some articles with no basis in fact.

Thus far the fact check tags seem to be most often triggered by long-existing false stories. For example, a search in Google's main search box of the phrase "kidney theft" give a top return that links to a Snopes.com article debunking a popular, and false, Internet topic about unwary travelers being drugged and used as unwilling kidney donors by organ thieves.

Some political topics are also present. Searching on "national parks coal mining" give as its first return a snippet from Snopes titled "Did President Trump Open National Parks and Wildlife Refuges for Coal Mining?" and the label of "Mixed" as to its truth.

President Trump did sign an executive order in March that overturned a temporary moratorium on the leasing of federal lands for coal mining, but Snopes noted that public lands had never been fully and permanently closed to such activity in the first place.

The phrase "30 million undocumented immigrants" brings up Google fact-check snippets because during the presidential campaign, Trump made the claim that the number of undocumented immigrants in the United States could be much higher than the 11 million previously reported by the U.S. government. “It could be 3 million. It could be 30 million," Trump said in a speech in Phoenix in August.

That number was actually pegged at 11.4 million by the federal government in 2012, a number corroborated by groups such as the non-partisan Pew Research Center.

The system isn't partisan and any fact check organization that wants to can take part, as long as it abides by Google's terms of service for fact check snippets, Google says. They require that analysis "be transparent about sources and methods, with citations and references to primary sources."

Each snippet also comes with a Feedback link for users to respond.

Google has been under pressure, both internally and externally, to provide more authoritative and truthful results. In December after it emerged that a Holocaust-denying site was the first one that popped up when someone searched “Did the Holocaust happen?” the company changed its algorithm to “help surface more high quality, credible content on the web,” reported tech news site Search Engine Land.

While such sites make up fewer than 1% of Google queries, the company clearly has begun to address the problem and has been putting a lot of resources into it, said Barry Schwartz, a news editor at Search Engine Land.

“If someone’s searching for something specifically, even if it’s rumor and not true, Google wants to show them that authoritative sites believe it’s not factual,” Schwartz said.