A study of language and literacy activities and attitudes in a southern California bilingual community and the resulting development of more culturally relevant writing instruction for junior and senior high school students of that community is reported. The initial task was an ethnographic survey of the community, focusing on its language activities and values. Four families were studied and compared, and the parents' perspectives examined. Based on these findings, appropriate writing activities were developed for this group and formulated into instructional modules, for which seminars were held to familiarize teachers with the materials and techniques. Modules were designed with content and activities relevant to students' everyday concerns and communication needs. The writing modules were then used in 3 junior high schools with 293 students. Evaluations of over 1,000 pre- and post-course writing samples showed a significant achievement gain during the period of the study. It is suggested that the potential role of ethnography in instructional reform is great, providing a key to instructional, motivational, and sociocultural congruence in the classroom for both teachers and students. (MSE)