The National Longitudinal Transition Study (NLTS) of Special Education Students provides ongoing information to the special education community regarding the transition of youth with disabilities from secondary school to early adulthood. The sample for the study began with a 1987 survey (Wave 1) involving more than 8,000 youth from the national population of secondary special education students. These subjects were again surveyed in 1990-91 (Wave 2). This report describes the data collection instruments and procedures used in Wave 2 of the NLTS. Data collection components for Wave 2 included parent/youth telephone interview and mail questionnaires (n=6,684), school transcripts (n=4,057), summaries of school programs, a school program survey, and a school background survey. Analysis centers on Wave 2 weighting, both in comparison to Wave 1 and in reference to specific samples for secondary program analysis, school services analysis, overall dropout analysis, estimated dropout analysis, school program survey analysis, analysis of trends in postschool outcomes, analysis of vocational rehabilitation services to out-of-school youth, service provision for out-of-school youth, and the contribution of school experiences to postschool outcomes. Analysis also details implications of the nonresponse bias. (DB)