SOURCE: Data from Westat (2002a: Table 1), amended according to personal communication from SRS staff. Notes: See text for discussion. For background information also see design and methodology report on the National Science Foundation SESTAT website (http://srsstats.sbe.nsf.gov/techinfo.html).

^aThe computed rates for 1995 and later are approximate. The committee acknowledges that these rates are based on assumptions that the committee has not been able to verify.

^bIn 1995 a subsample of mail nonrespondents was selected for computer-assisted telephone interview (CATI) follow-up. The unweighted response rate using the total sample (including those subsampled out) as the base is 77 percent. The weighted response rate was 85 percent, as shown in the table.