This "Guide" is intended for staff developers and assessment planners already familiar with current educational assessment reform. Performance assessment means measuring the growth or achievement of one student's performance against an established set of standards for quality, the "performance standards." Students usually demonstrate their knowledge and understanding by completing a performance task. The focus of this guide is to ensure that the language and cultural demands of performance tasks are understood and considered during development, administration, and interpretation. Part 1 of the "Guide" provides background information related to the role of language and culture in performance assessment. Part 2 focuses more closely on adaptation or development of the performance tasks themselves and includes sample tasks. Part 3 suggests a workshop for staff developers to promote awareness of assessment principles and procedures. Eight transparencies are illustrated in the text, and the templates for these transparencies are presented in an appendix. (Contains 3 figures and 33 references.) (SLD)