Examines the central characteristics of interlanguages that distinguish them from all other natural language systems. It is proposed that, since permeability presupposes an interlanguage norm which is relatively stable, we are forced to gather enough data to establish the overall level of linguistic competence of the learner. (Author/POP)

A cybernetic model of factors involved in the fossilization of grammatical and lexical forms in learner grammars is offered. A distinction is made between affective and cognitive dimensions of a multidimensional channel of human communication; and the effect of expected and unexpected feedback on these two dimensions is discussed. (Author/POP)

This paper presents a case study of the untutored acquisition of English by a 33-year-old Costa Rican male. Three causes for his lack of linguistic development over a 10-month period are considered: ability, age, and social and psychological distance. The third of these is seen as the cause. (Author/POP)

Explores the validity of Labov's (1969) "Observer Paradox," and the five axioms describing the problems involved in linguistic research, for interlanguage research. Methodological remedies are suggested. (AM)

Presents arguments for the view that pidginization can be a model of early second language acquisition, decreolization can be a model for later second language acquisition, and creolization is inappropriate for any aspect of this process. (Author/AM)

This article reports major findings of a longitudinal, naturalistic study of the acquisition of English as a second language by a five-year-old Japanese girl. The emphasis is on empirical findings rather than on any particular theoretical orientation. (Author/POP)