Appendix A
Sample Design and Fieldwork

The sample was designed to represent the population of the Republic of Korea age 20 and over. The 2000 report of the Population and Housing Census of the national Statistical Office was used to first stratify the population by the eight provinces (Do) and the seven large cities on the basis of their proportionate share of the national population. The island of Jeju-Do, with 1.1 percent of the total population, was excluded. Secondly, each province or large city was stratified by administrative subdivisions (Dong, Eup and Myeon) on the basis of its proportion of the population. At the third stage, the primary sampling units (ban or village) were randomly selected with six to eight households in a ban and twelve to fifteen in a village. At the household level, the interviewer was instructed to select for interview the person whose birth came first.

Fieldwork was undertaken by regularly employed interviewers of the Garam Research. Each interviewer participated in a one-day orientation session and completed three trial interviews. A random selection of 20 percent of interviews was independently validated. All interviews were face to face. Fieldwork started on 10 February and ended on February 22, 2003. If no one was at home at a household or if the adult selected for interview was not at home, the interviewer was instructed to call back three times. A total of 3,224 addresses were selected. At 649 addresses, there was no one at home after three callbacks, so that the household residents could not be listed and a respondent selected. Of the 2,575 households where an individual name could be selected by the birthday method, 32 individuals were not interviewed because they were too old or infirm or absent from the household; 630 refused; and 413 were not completed because of the respondent’s impatience, for which Koreans are notorious. A total of 1,500 interviews were satisfactorily completed, registering a response rate of 58 percent. The mean length of interviews was 60 minutes; the range was from 50 to 90 minutes.