Survey data for majority and minority ethnicities in Bulgaria, Hungary, Romania and Russia illustrate how internal ethnic identification and other social characteristics influence external ethnic classification. Logistic regressions show how interviewers use negative social characteristics (poverty, low education) to classify respondents as Roma (Gypsies) who did not self-identify as such. In contrast, for other minorities (Hungarians in Romania, Ukrainians in Russia) and majorities, these characteristics had the opposite or little effect, though self-identification, parents' ethnicity and language were influential. Interviewers' classifications tend to include, not exclude, these ethnicities as majorities. Thus, classifications are external and exclusionary for the racialized ethnicity, Roma, while classifications are optional and inclusive for other ethnicities. (Contains 2 tables and 13 notes.)