This study is based on the 2009 Parent-Teen Cell Phone Survey which obtained telephone interviews with a nationally representative sample of 800 teens age 12-to-17 years-old and their parents living in the continental United States and on 9 focus groups conducted in 4 U.S. cities in June and October 2009 with teens between the ages of 12 and 18. The survey was conducted by Princeton Survey Research Associates International. The interviews were done in English by Princeton Data Source, LLC from June 26 to September 24, 2009. Statistical results are weighted to correct known demographic discrepancies.

The margin of sampling error for the complete set of weighted data (n=800) is ±3.8%. Margins of error for subgroups may be larger than the margin of error for the total sample. For example, the findings for teen cell owners are based on a subsample of 625 teens and have a margin of error of ±4 percentage points; the findings for teen texters are based on a subsample of 552 teens and have a margin of error of ±5 percentage points. Sampling errors and statistical tests of significance in this study take into account the effect of weighting (described later in "Weighting and analysis").

Focus Groups

The qualitative data comes from focus groups conducted by the University of Michigan and the Pew Research Center’s Internet & American Life Project. Three of the focus groups were conducted in one city in June 2009 and 6 more groups were held in 3 cities in October 2009 with teens between the ages of 12 and 18. Three of the groups were mixed sex and six of the groups were single sex – 3 groups with each sex. Three of the groups were with middle schoolers and 6 were with high school-aged students. Every effort was made to secure a diverse group of participants, with a balance of teens from different racial and ethnic backgrounds and socio-economic levels. All teens who participated in the focus groups had a cellular phone. Participants were offered a cash incentive for participation.

Each focus group lasted approximately 90 minutes, and the 6 October groups included an individually administered paper questionnaire with additional questions that was completed during the 90 minute session. Recruitment for the focus groups was done by Scott Campbell and Resolution Research LLC of Denver, Colorado. Focus groups were moderated by Amanda Lenhart of Pew Internet and Scott Campbell of the University of Michigan, usually in teams of two, with one lead moderator and one secondary moderator. University of Michigan graduate students also attended the focus groups.

Further details on the design, execution and analysis of the quantitative telephone survey are discussed below. For those interested in calculating the margin of error for various subgroups mentioned in this report, please see the section titled "Effects of Sample Design on Statistical Inference" for the formula for that calculation.