In sum, accurately predicting the cognitive, as well as social and behavioral, outcomes of intervention programs is difficult because of the numerous variables that must be taken into account, including quality of the mother-infant relationship, socioeconomic status of the family, educational level of the parents, stress on the family and coping skills, available family supports, temperament and gender of the child, spacing of the siblings, age at which the child enters the program and for how many hours per day, quality of the caregiver-infant relationship, caregiver-parent communication, and quality of the program