<P> Attachment in adults is commonly measured using the Adult Attachment Interview, the Adult Attachment Projective Picture System, and self - report questionnaires . Self - report questionnaires assess attachment style, a personality dimension that describes attitudes about relationships with romantic partners . Adult attachment style is thought to be similar to childhood attachment patterns . There is some research that shows a link between childhood attachment patterns and attachment personality dimensions with romantic partners, but correlations are mild to moderate . The most common approach to defining attachment style is a two - dimension approach in defining attachment style . One dimension deals with anxiety about the relationship, and the other dimension dealing with avoidance in the relationship . Another approach defines four adult attachment style categories: secure, preoccupied, dismissive - avoidant, and fearful - avoidant . </P> <P> Some methods are based on observation of infants and toddlers either in natural or' arranged' situations . Other methods, suitable for older children, are based on asking children to complete "attachment story stems," draw a picture of their family, or describe their relationships . </P> <P> The Strange Situation procedure was formulated to observe attachment relationships between a caregiver and children between the age of nine and 18 months . It was developed by Mary Ainsworth, a developmental psychologist Originally it was devised to enable children to be classified into the attachment styles known as secure, anxious - avoidant and anxious - ambivalent . As research accumulated and atypical patterns of attachment became more apparent it was further developed by Main and Solomon in 1986 and 1990 to include the new category of disorganized / disoriented attachment . </P> <P> In this procedure the child is observed playing for 20 minutes while caregivers and strangers enter and leave the room, recreating the flow of the familiar and unfamiliar presence in most children's lives . The situation varies in stressfulness and the child's responses are observed . The child experiences the following situations: </P>

Who designed the strange situation to measure attachment