Nearly 20 percent of people say they are undecided about participating in this year's census, the government's once-a-decade attempt to paint a new portrait of the country.
According to a new poll released Wednesday by the Pew Research Center, 10 percent of people said they might or might not participate, 4 percent probably will not, 2 percent definitely will not, and another 2 percent do not yet know if they will take part.
The census kicks off later this year when the 10-question form arrives in mailboxes nationwide in March, followed by National Census Day on April 1.
When Pew interviewed over 1,500 adults by phone from Jan. 6-10, they found that 58 percent of Americans will definitely participate in the survey, while another 23 percent probably will.
But a lack of awareness about what the census does, the Pew poll found, is a key factor in determining participation.
"The key driver of uncertainty about participation is lack of awareness about the census and what it's used for," said Scott Keeter, director of survey research for the Pew Research Center, in an interview with ABC News.
For instance, 21 percent of people incorrectly said that the census is not used to decide how government tax revenues are distributed, while another 20 percent said they did not know.
"The more general problem, I think, is that people don't understand why it's valuable to take part in the census," Keeter said.
For the federal government's Census Bureau, getting Americans to take part in the decennial count is not only crucial, but it is also cost-effective. For every 1 percent increase in the number of people who mail back their census forms, the bureau saves $80 million.
But a recent analysis conducted by the bureau predicted a possible 3 percent decrease in mailed-back forms this year, due to recent increases in government mistrust, identity theft, and home foreclosures.
In an effort to boost participation, the bureau earlier this month launched a $340 million promotional campaign to alert the nation about the census. The bureau's road tour will stop at over 800 events nationwide, with 13 tour vehicles logging more than 150,000 miles in an effort to "bring the census to life."
The road tour, wrote Census Bureau director Robert Groves in a December blog post, will help the public "learn about the 2010 census and how participation supports local communities."
However, teaching people about the census can be a tall order since some Americans have mistaken impressions about the government count.
For example, the Pew poll found that 11 percent of people mistakenly believe that the census is used to locate illegal immigrants for arrest.
"The census is not used for immigration enforcement, but if there's a misconception about that in the Latino community, then people may not be willing to take part in the census," noted Keeter.
Overall, Hispanic Americans and younger Americans, the Pew survey found, are the groups most unfamiliar with the census. Approximately a third of each group – 33 percent of Hispanics and 31 percent of 18-29 year olds – said they had not even heard of the census.