SAN FRANCISCO -- Google is pulling another lever on its influential search engine in an effort to boost voter turnout in November's U.S. presidential election.

Beginning Tuesday, Google will provide a summary box detailing state voting laws at the top of the search results whenever a user appears to be looking for that information. The breakdown will focus on the rules particular to the state where the search request originates unless a user asks for another location.

Google is introducing the how-to-vote instructions a month after it unveiled a similar feature that explains how to register to vote in states across the U.S.

The search giant said its campaign is driven by rabid public interest in the presidential race between Hillary Clinton and Donald Trump. As of last week, it said, the volume of search requests tied to the election, the candidates and key campaign issues had more than quadrupled compared to a similar point in the 2012 presidential race.

TURNOUT EFFECTS

It's difficult to predict whether Google's efforts will have a major impact on how many people cast ballots, says Michael McDonald, a University of Florida political scientist who closely studies election turnout.

That's because Google will narrowly target its voting instructions to people who are actively seeking that information. Sample requests that will elicit a helping hand from Google include "what do I need to vote," "when can I vote," "what is the absentee ballot deadline" and "can I vote by mail."

The summary boxes won't appear for broader requests pertaining to the election, such as "Clinton" or "Trump."

That means Google may primarily end up helping out "politically engaged" people who'd be likely to cast a November ballot even without prodding from the world's most popular search engine. "It's an open question on how large the positive effect will be," McDonald said.

ONLINE PRODDING

Other online services have previously tried to encourage more people to vote. In the November 2010 midterm election, for instance, Facebook posted a "get out the vote" message in the news feeds of about 60 million people on its social network. A University of California at San Diego study of that Facebook effort estimated it boosted voter turnout by about 340,000 people.

Google will also release its registration and voting guides to non-profit groups and other organizations aiming to get more people to the polls this November. The company said it considers its voting tools to be a nonpartisan public service, although swings in voter turnout have swayed past elections.

McDonald, though, says it is always difficult to predict which candidate in an election stands to gain the most from an increase in voter turnout. As an example, he suggests, Google's effort could easily help increase the number of younger people more inclined to vote for Clinton -- or put more ballots in the hands of less educated, disillusioned citizens backing Trump.