Setting, instrumentation, and variability problems are also covered. Chapter 3 focuses on the development of modes of inquiry and the evolution of issues since the inception of SLA research. Contrastive analysis, error analysis, performance analysis, and discourse analysis are all discussed from an historical perspective. These data analysis procedures evolved from successive realizations of the complexity and extensiveness of SLA and each subsumed rather than replaced its predecessor. Chapter 4 continues the discussion of IL and presents substantive research findings relating to this concept.
Variability is treated extensively.
The analysis of developmental sequences includes the morpheme studies as well as those dealing with interrogatives and negation. A large body of research on input modification and L2 comprehension is reviewed. Finally, the relationship between comprehensible input and SLA is discussed. Chapter 6 addresses individual learner variables and differen- tial L2 achievement. Other learner variables discussed are aptitude, socio-psychological factors such as motivation and attitude, cognitive style and hemispheric specialization, personality, and learning strategies.