This handbook provides an integrated discussion of key issues in second language acquisition (SLA). The 24 chapters include the following: (1) "The Scope of Inquiry and the Goals of SLA" (Catherine J. Doughty and Michael H. Long); (2) "On the Nature of Interlanguage Representation: Universal Grammar in the Second Language" (Lydia White); (3) "The Radical Middle: Nativism without Universal Grammar" (William O'Grady); (4) "Constructions, Chunking, and Connectionism: The Emergence of Second Language Structure" (Nick C. Ellis); (5) "Cognitive Processes in Second Language Learners and Bilinguals: The Development of Lexical and Conceptual Representations" (Judith F. Kroll and Gretchen Sunderman); (6) "Near-Nativeness" (Antonella Sorace); (7) "Language Socialization in SLA" (Karen Ann Watson-Gegeo and Sarah Nielsen); (8) "Social Context" (Jeff Siegel); (9) "Input and Interaction" (Susan M. Gass); (10) "Instructed SLA: Constraints, Compensation, and Enhancement" (Catherine J. Doughty); (11) "Implicit and Explicit Learning" (Robert DeKeyser); (12) "Incidental and Intentional Learning" (Jan H. Hulstijn); (13) "Automaticity and Second Languages" (Normal Segalowitz); (14) "Variation" (Suzanne Romaine); (15) "Cross-Linguistic Influence" (Terence Odlin); (16) "Stabilization and Fossilization in Interlanguage Development" (Michael H. Long); (17) "Maturational Constraints in SLA" (Kennety Hyltenstam and Niclas Abrahamsson); (18) "Individual Differences in Second Language Learning" (Zoltan Dornyei and Peter Skehan); (19) "Attention and Memory During SLA" (Peter Robinson); (20)"Language Processing Capacity" (Manfred Pienemann); (21) "Defining and Measuring SLA" (John Norris and Lourdes Ortega); (22) "Data Collection in SLA Research" (Craig Chaudron); (23) "SLA Theory: Construction and Assessment" (Kevin R. Gregg); and (23) "SLA and Cognitive Science" (Michael H. Long and Catherine J. Doughty). (Papers contain references.) (SM)