A stratified, multistage and cluster sampling design was adopted. The 2000 Population Census at the Korea National Statistical Office was the sampling frame. Face-to-face interviews were conducted among a total of 7,867 sample persons and the response rate was 79.8%. The technical details of the Korean version of the CIDI 2.1 can be found in an earlier publication by Cho and his colleagues (Cho et al., 2002).
