This chapter addresses issues of action research from three perspectives. In the first section, what it means to engage in action research as a methodology for investigating teaching and learning in science education is overviewed and various conceptions of action research are explicitly made. The second perspective is that of an individual engaged in action research in the classroom to improve teaching, students' learning, and advance knowledge of the teaching and learning of physics. The third perspective is that of a facilitator of action research done by others. By providing views from these three perspectives, the concerns and issues of action research are addressed and helps readers develop their own understanding of what action research is and can be so that it can be used as a methodology for the study of teaching and learning in science. (KHR)