When the traditional opportunities for professional renewal do not seem adequate or appropriate to teachers of English as a second language (ESL), one means of professional development is self-initiated, naturalistic research in curriculum and instructional development. However, individual action research has the limitations of one person's time, resources, and perspective. Collaborative, self-evaluative research accomplished through a network of teachers can be more effective and allows for development in the areas of instructional evaluation, curriculum development, instructional innovation, and curriculum evaluation. The education of ESL teachers should include instruction in systematic experimentation and self-evaluation. Because of the limitations of professional conditions within a single school, mechanisms for interinstitutional networking should be developed among private sector teachers. Groups and schools interested in self-monitoring and development must acquire naturalistic research skills and use them systematically, while allowing research projects to begin modestly and to evolve according to local needs and circumstances. A paper on the "TIQL" teacher-based research project is appended. (MSE)