How is the Strange Situation used to study attachment in young children? What are typical patterns of findings?

A good answer would include the following key points:
-One-year-old children and their mothers report to a laboratory, where they meet another adult.
-The mother then leaves the room, prompting most babies to cry and become upset.
-When the mother returns, differences in attachment are seen.
-Securely attached babies tend to smile and look happy to see their mothers.
-Anxious babies continue crying even after the mother's return and remain difficult to comfort.
-Avoidant babies look away from their mothers and refuse to acknowledge them.