There were seven stages which each lasted 3 minutes:
1. the caregiver enters a room, places the child on the floor and sits on a chair, the caregiver does not interact with the child unless the infant seeks attention
2. a stranger enters the room, talks to the caregiver and then approaches the child with a toy
3. the caregiver exits the room, if the infant plays the stranger observes without interruption, if the child is passive, the stranger attempts to interest them in the toy, if they show distress the stranger attempts to comfort them
4. the caregiver returns while the stranger then leaves
5. once the infant begins to play again, the caregiver may leave the room, leaving the child alone briefly
6. the stranger enters the room again and repeats behaviour mentioned in step 3 (observing, engaging, comforting as needed)
7. the stranger leaves and the caregiver returns