All interviews were done by telephone using live interviewers from EMH Research, based in Sacramento. Subjects were randomly selected from a list of registered voters statewide and were reached on land lines or cellphones depending on the numbers they designated on their voter registrations. The percentage of cellphone respondents in the study matches the percentage of those who list a cellphone as their primary phone on the voter file.
Bilingual dialers gave respondents the option of taking the survey in English or Spanish. Up to five attempts were made to reach and interview each randomly selected voter. In order to include a wider range of questions in this study within the allotted time, some batteries of related questions were split into random half-samples of 750 voters each.
Upon completion of the interviewing, the results were weighted slightly to more accurately reflect the total population of registered voters throughout the state. Weighting was done to regional and demographic characteristics according to known census estimates and voter file projections; party registration was weighted to match the 2009 report from the California Secretary of State's office.
The margin of sampling error for results based on the overall sample of 1,500 registered voters is +/- 2.6 percentage points at the 95% confidence level. The margin of error for the findings from each half-sample of 750 registered voters is +/- 3.6 percentage points.
This survey was conducted for the Los Angeles Times and the University of Southern California College of Letters, Arts and Sciences by Greenberg Quinlan Rosner in conjunction with Public Opinion Strategies, both based in Washington, D.C.