This paper reports two studies which examined sequential dependence in the dyadic interaction between mother and infant. In the first study, brief videotaped behavioral samples were collected for 24 primiparous mother-infant (M - I) dyads to examine the degree of reciprocal contingency in M - I interactions. Two coders, using a computer interfaced event recorder, produced separate, continuous records for mother and infant of the sequence and duration of the binary states (present or absent) of facial gaze (FG) and vocalization (VOC) over 3 minutes of interaction. Among the results, mothers spent more time (92%) than infants (46%) in FG and similarly more time (41%) than infants (6%) in VOC. Mother initiated activity occurred more often than infant initiated activity. Infants showed a higher probability of terminating episodes of mutual FG and VOC. Outcomes of data shuffling and simulations of M - I interaction suggest that initially the M - I dyad may be a system that does not depend on the maintenance of a precise contingency between the activities of its components. Applying a continuous time Markov model to the continuous records, Study II (a larger study of 60 primiparous mothers with female infants at 12, 14 and 16 weeks of age) suggests that there are dependent components in the mothers' behavior. The infant seems to look and vocalize independently of the mother's behavior. Mothers apparently structure their behavior so that their infants can acquire basic rules of communication. (Author/RH)