Two studies investigated the modification of tasks by students in different public school settings. The first study examined task modification in physical education settings and the second study considered task modification by learning disabled students in a resource room and in two mainstream settings. In study 1 a systematic observation system was used to describe interactions among students, teachers, and the environment. Teacher task statements, student tasks, student responses, and response consequences were classified. Subjects were nine physical education teachers and one target student in each of 24 lessons. The special education study involved similar classification of interactions during 72 lessons involving two 14-year-old eighth grade learning disabled males. Results of both studies indicated very low levels of student verbal negotiation in modifying tasks. Students modified tasks in the physical education setting by engaging in the task with a high rate of error. Learning disabled students were more likely to emit responses which did not comply with or which only partially complied with the stated instructional tasks. Results confirm previous studies' findings that ability level of the student and the amount of risk involved in tasks is related to how students attempt to modify them. Includes 14 references. (DB)