The Teacher Observation in Preschools (TOP) is a system for observing teachers’ and assistants’ behaviors in preschool classrooms across a day-long visit. The TOP is based on a series of snapshots of the teacher’s and assistant’s behaviors across a period of time. Each snapshot may be, by itself, an unreliable piece of information, but collectively, they combine to provide a picture of how the teacher and assistant are spending their time in a classroom. The TOP is used in conjunction with the Child Observation in Preschool (COP), a system that focuses on children; the TOP has never been used independently of the COP. (author abstract)