Assessment can happen anywhere and everywhere. Since Head Start is government funded, formal assessment is required. However, teachers do still rely on observation, anecdotal, and other informal assessment.
During free choice, teachers find a spot in the room where they can observe. They only interfere if necessary.
In many Head Start classrooms, the curriculum can be tweaked by the teacher. The teacher may change next week's unit based on what they heard the kids chattering about in the bathroom, yesterday.
...and their social/emotional well being.
We employ a curriculum called Teaching Strategies Gold which helps to assess where children are now and how teachers can plan individualized, developmentally appropriate activities.