1983 ORANGE COUNTY SURVEY

                                          METHODOLOGY

A. Sample
The sample for the 1983 Orange County Survey consists of 1,003 randomly selected residents who were 
interviewed by telephone.  The sample is stratified geographically, with half of the sample selected from 
the north of the Santa Ana River and half from the south.  For data analyses, the sample is statistically 
weighted to represent the actual distribution of the Orange County population. 
	The sample in each area was chosen using a computer program, which randomly generates telephone 
numbers from among working blocks of telephone exchanges.  A working block is one that contains numbers 
in use.  The total of telephone numbers generated within an exchange was in proportion to the number of 
residential phones represented by that exchange in the northern part of the county or the southern part 
of the county.  Using this procedure, approximately 1,800 telephone numbers from the south and 
approximately 1,800 telephone numbers from the north were drawn.  This procedure of random digit dialing 
ensures that unlisted as well as listed numbers are included in the sample.  Also, since 95% of the 
households in Orange County have telephones, random dialing yields a sample representative of the 
population of Orange County.
	The Troldahl-Carter Method was used in randomly selecting which adult member of the household was 
to be interviewed.2  This method consists of enumerating the total number of adults in the household and 
the total number of men in the household.  Then, using a prearranged grid, the interviewer selects the 
individual in the household for interviewing.
	As further evidence of the representativeness of the sample chosen by the above methods, 
characteristics of the sample were compared to characteristics of the total Orange County population 
using the 1980 census.  On the basis of age, income, sex, marital status, household size, and home 
ownership, the sample is representative of the population of Orange County.  Characteristics of the 1982 
Orange County Survey sample were also contrasted with the characteristics of the 1983 Orange County 
Survey sample.  Marital status, ethnicity, age, sex, and education were closely comparable in the two 
surveys. 
	The sampling error for this survey is plus or minus three percentage points.  This means that if 
this survey were to be repeated on hundred times, in 95 out of the 100 times the answers obtained for a 
particular question would match those we obtained in this survey within three points.  The sampling error 
for any particular sub-group would be greater.  These calculations assume that the data were collected 
under ideal circumstances.  Since there are a large number of practical problems in conducting social 
surveys, the actual sampling error for any particular result might be slightly larger.

B. Data Collection and Survey Instrument
	As noted above, the interviewing for the Orange County Survey was done by telephone.  Cost considerations 
and methodological improvements have led to telephone surveys' increased adoption in the social sciences.  
In addition, several studies show similar quality in telephone and face-to-face interviews. 
	Interviewers were closely supervised during the data collection.  Interviewers participated in a 
two-hour training session on the Orange County Survey instrument.  Supervisors were available during the 
telephone interviewing to answer questions of interviewers or respondents.  The telephone system used 
also allowed supervisors to monitor interviews to correct for errors in administering the questionnaire.