Strategists affiliated with the Obama and Romney campaigns say they have access to information about the personal lives of voters at a scale never before imagined. And they are using that data to try to influence voting habits — in effect, to train voters to go to the polls through subtle cues, rewards and threats in a manner akin to the marketing efforts of credit card companies and big-box retailers.

In the weeks before Election Day, millions of voters will hear from callers with surprisingly detailed knowledge of their lives. These callers — friends of friends or long-lost work colleagues — will identify themselves as volunteers for the campaigns or independent political groups.

The callers will be guided by scripts and call lists compiled by people — or computers — with access to details like whether voters may have visited pornography Web sites, have homes in foreclosure, are more prone to drink Michelob Ultra than Corona or have gay friends or enjoy expensive vacations.

The callers are likely to ask detailed questions about how the voters plan to spend Election Day, according to professionals with both presidential campaigns. What time will they vote? What route will they drive to the polls? Simply asking such questions, experiments show, is likely to increase turnout.