Currently, nearly half of Americans have only a cellphone. Because many people can no longer be reached by landline telephone, the representativeness of telephone surveys based only on a random sample of households with landline telephone service has come under increased scrutiny. Many pollsters and survey methodologists, including those at Pew Research Center, are studying how cellphones impact telephone surveying. Public Opinion Quarterly dedicated a special issue to the topic of cellphones in 2007: Cell Phone Numbers and Telephone Surveying in the . Pew Research Center began routinely including a cellphone sample in nearly all of its surveys in 2008.