How the poll was conducted
The Los Angeles Times/USC College of Letters, Arts and Sciences poll was conducted by Greenberg Quinlan Rosner in conjunction with American Viewpoint, both based in Washington, D.C.
The findings are based on a random sample survey of 1,515 registered voters in California conducted from March 23 to 30, 2010.
All interviews were done by telephone using live interviewers from the ISA Research facility in Van Nuys. Voters were randomly selected from a list of registered voters statewide and reached on land line or cellphone, depending on the numbers they designated on their voter registration. The percentage of cellphone respondents in this study matches the percentage of those who listed their cellphone 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, some batteries of related questions were split into random half-samples of 757 voters each for purposes of time.
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 Bureau estimates and voter file projections; party registration was weighted to match the most recent 2010 report from the California secretary of state’s office.
The maximum sampling error for results based on the overall sample of 1,515 registered voters is plus or minus 2.6 percentage points at the 95% confidence level. The margin of error for the findings from each random half-sample of 750 registered voters is plus or minus 3.6 percentage points.