The growing popularity of mobile phones is becoming a challenge to market research groups when getting representative samples to back up their studies.



According to The New York Times, low response rate is a big concern when conducting surveys via mobile phones since most people are hesitant to shoulder the call charges.

The Pew Research Center conducted four studies last year on the differences between cellphone and land line respondents. The studies said the differences were not significant enough to influence surveys properly weighted to census data. With the increase in cellphone-only households, that may not be the case next year. Researchers, including the New York Times/CBS News poll will test that by incorporating cellphones in samples.

Before, a phone survey is done by calling random numbers in every region coming from a list of area codes. With the number of cellphone-only households is significant growing from 3% in 2003 to 16% this year. It is expected to reach 25% by the end of 2008.