A study was conducted to examine children's developing perceptions of contextual factors surrounding their writing at home and at school. Subjects were 20 children from grades one through five, who wrote in a wide range of contexts. Children's writing products for three months were labeled for ownership, setting, audience, purpose, and genre, during interviews conducted every three weeks. Based on these interview data, categories of five contextual factors were defined. The products and categories of the 10 most extensive writers were further analyzed to examine the range of audiences, purposes, and genres occurring by grade level within three common writing situations: (1) spontaneous writing at home, (2) spontaneous writing at school, and (3) assigned writing primarily at school. At all grades children cited more audiences, purposes, and genres for their spontaneous writing than for assigned writing. While the number of categories remained fairly stable after grade 1 for assigned writing, the number cited for spontaneous writing generally increased across grade levels. Within spontaneous writing, the number of categories listed for each factor moved from emphasis at home in grade one to school by grade three and back to both settings by grade five. The results suggest that restructuring the classroom to allow for real, rather than assigned, constraints may allow children more natural and extensive development as writers. (A list of categories of contextual factors is appended.) Tables of findings are included. (HOD)