UCI

Survey Methodology

The Orange County Annual Survey, UCI was co-directed by Mark Baldassare, professor and chair of urban and regional planning, and Cheryl Katz, research associate. The random telephone survey included 1,007 Orange County adult residents interviewed August 20 to 29, 1993. We follow the methodology used in the 11 previous surveys.

Interviewing was conducted on weekend days and weekday nights, using a computer-generated random sample of telephone numbers. Within a household, adult respondents were randomly chosen for interview. Each interview included 94 questions and took an average of 20 minutes to complete. The interviewing was conducted in English and Spanish, as needed.

The completion rate for the survey was 63 percent. This rate is consistent with earlier Orange County Annual Surveys. Of the telephone numbers called, 20 percent resulted in completed interviews and 12 percent were refusals. The field work was conducted by Interviewing Services of America of Van Nuys, CA.

The sample was compared to the 1990 U.S. Census population figures by city for Orange County and was found to represent the actual regional distribution of Orange County residents.

The sampling error for this survey is +/- 3 percent at the 95 percent confidence level. This means that 95 times out of 100, the results will be within 3 percentage points of what they would be if all adults in Orange County were interviewed. The sampling error for any subgroup would be larger. Sampling error is just one type of error to which surveys are subject. Results may also be affected by question wording, ordering, and survey timing.