In the study reported, we examine the evolution of preservice teacher observation, focusing on the essential nature of observation to preservice teachers' learning about teaching while in the field. The study was 3 years long, and it involved 79 preservice teachers during semester-long language arts methods courses in early childhood and middle childhood. A theory-to-practice tool was originated and used to assist preservice teachers. Data collected were analyzed with a content analysis technique. We contend that it is not enough to be placed in a classroom to passively observe teachers and students. Preservice teachers must engage in the act of observation and reflect on the importance of those observations in learning about teaching.