Part of a series designed to provide practical resources for transition personnel on a variety of topics essential to the process of preparing individuals with disabilities for adulthood, this guide focuses on assessment for transition planning. Chapter 1, "Transitions Assessment: What Do We Need To Know about Students and Why?," discusses the foundation for transitions assessments, Including primary assessment areas, descriptions of transitions assessment areas, and purposes of transitions assessment. Chapter 2, "Obtaining Transitions Assessment Data through Standardized Instruments," explains standardized assessment instruments, provides examples of standardized tests specifically designed for transitions planning with adolescents, and explores the limitations of standardized assessments. Chapter 3, "Obtaining Transitions Assessment Data through Informal Instruments," describes basic guidelines for locally developed informal assessments, using informal assessment data for transitions planning, person-centered planning as an assessment approach, computerized assessment systems, environmental assessments, curriculum-based assessments, and medical appraisals. The final chapter, "Conducting Transitions Assessments in Schools," discusses who should be responsible for transitions assessments, sensitivity to gender and cultural diversity, kinds of testing accommodations, and recommendations for transition assessments. Appendices include a list of standardized instruments, sample items from the Life-Centered Career Education Competency Assessment Performance Batteries, and planning profiles. (Contains approximately 100 references.) (CR)