This issue of The Journal of Social Issues is devoted to nine articles on the topic of bilingualism written by authorities in the fields of linguistics, anthropology, sociology, psychology, and education. The authors and their topics are: (1) Dell Hymes, "Models of the Interaction between Language and Social Setting," (2) Joshua A. Fishman, "Bilingualism With and Without Diglossia; Diglossia With and Without Bilingualism," (3) Heinz Kloss, "Bilingualism and Nationalism," (4) John J. Gumperz, "On the Linguistic Markers of Bilingual Communication," (5) John Macnamara, "The Bilingual's Linguistic Performance--A Psychological Overview," (6) Susan Ervin-Tripp, "An Issei Learns English," (7) Wallace E. Lambert, "A Social Psychology of Bilingualism," (8) A. Bruce Gaarder, "Organization of the Bilingual School," and (9) John Macnamara, "The Effects of Instruction in a Weaker Language." (JD)