Strength)Good reliability
->A team of trained observers found agreement on attach type in almost all cases. This high level of reliability may be because the procedure is done in controlled conditions.
Limitation)Not a valid measure of attachment in different cultural contexts.
->S.S was made in US, by US standards. A baby from Germany may be tested as insecure-avoidant because of the culture they were raised in but in Germany it wouldn't be classed as that because those characteristics are desired and nurtured in babies.
Limitation) Takes place in a controlled, unfamiliar lab setting with a stranger, which might not reflect real-life interactions. The artificial environment could influence a child’s behaviour (e.g. becoming more distressed than usual), meaning the attachment type observed might not accurately reflect how the child typically responds in natural settings.