Washington ? How will Americans use the Internet in 2020? Will we all use cell phones? Will we still have snail mail?

Experts at the U.S. Census Bureau are asking those questions in preparation for the 2020 count, even as temporary workers are knocking on doors to complete the 2010 Census.

Final answers won’t be needed for about eight years, but the team hopes to keep costs below the $14.7 billion budgeted for the 2010 Census and to make it possible for at least some Americans to answer questions via the Internet.

“None of us can imagine doing a 2020 Census without an Internet option,” Census Bureau Director Robert Groves said. Although he’s overseeing the current census, most of his tenure will be tied to 2020 preparations — and he’s pushing for a more efficient operation with fewer people.

“The easiest way to reduce costs in the census is to reduce manpower,” Groves said. “To the extent that we can reduce the number of census worker visits in 2020, we’re going to save a lot of money.”

Groves and his colleagues think they should wait until 2017 or 2018 to finalize plans on the Internet option to avoid making a technologically obsolete decision.

Lawmakers might force the bureau to move faster: Bills moving through the House and Senate with bipartisan support would require Groves to present plans on how to test and implement an Internet response option within six months of the bill’s passage. The agency’s inability to test and use expensive handheld computers for this year’s count has led some critics to question whether it can make a decision in the next 10 years. Groves dismissed those concerns.

“We can do this. I’m very optimistic,” he said.

In addition to cutting labor costs, allowing Americans to answer decennial census questions on the Internet would help cut the bureau’s costs for postage, printing and paper and could get data to the agency faster. Most especially, Groves said, “our guess is the Web will really be great for those people who are difficult to contact in person who are at home very infrequently,” thus reducing the need for door-knocking census takers.

But “we won’t go to 100 percent Internet, because it won’t work,” Groves said. A Web-only effort would make it harder to count those in rural areas or illiterate people, so the agency would continue to rely on paper questionnaires, in-person interviews and maybe telephone calls, he said.

Internet options will be tested in the next 10 years with the annual American Community Survey, which tracks demographic and economic statistics. Although details are sketchy, Groves said he expects the agency to send the questionnaire in paper format with an Internet address and code allowing people to submit answers online. Confidence in the online option might increase if respondents can first review the answers in print, he said.

Canada did something similar in 2006, and 18.6 percent of respondents replied online, said Mark Hamel, manager of the 2011 census for Statistics Canada, the Canadian equivalent of the U.S. Census Bureau.

Every Canadian household received a paper form with a secure access code, and the agency used a computer network with double encryption similar to the security features used for online banking, he said.