who developed an effective method for measuring attachment
Attachment measures 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[3] 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.[4][5]
Edward C. Tolman Tolman's theoretical model was described in his paper "The Determiners of Behavior at a Choice Point".[15] The three different variables that influence behavior are: independent, intervening, and dependent variables. The experimenter can manipulate the independent variables; these independent variables (e.g., stimuli provided) in turn influence the intervening variables (e.g., motor skill, appetite).[15] Independent variables are also factors of the subject that the experimenter specifically chooses for. The dependent variables (e.g., speed, number of errors) allows the psychologist to measure the strength of the intervening variables.[15]