Survey data on bilingualism among Indonesian adolescents from four ethnic groups: Javanese, Toraja, Batak, and Chinese. Data was collected between February to October 2017 in Toraja, Java, and in Sumatra (Indonesia).

SPSS, 23

The data relates to 5 languages: Bahasa Indonesia, Javanese, Batak, Toraja, and Mandarin Method: Data was taken in high schools in Java, Sumatra, and Sulawesi islands in Indonesia by the first author. Local assistants were recruited from the universities and institutes in Indonesia (Sanata Dharma University, Gadjah Mada University, STT SAAT, STT Jaffray). It was a survey and all questionnaires were given during the school hours with the consent of the schools, parents, and respondents. Universe: Age of respondents are between 12-19 years old, all are Indonesians from four ethnic groups: Javanese (from Java), Batak (from North Sumatra), Toraja (From Toraja, South Sulawesi), Chinese (from Java and Sumatra).

DSA proof