Many explanations for the current findings of limited group differences between premature and term infants at comparable conceptional ages can be imagined that remain buried in the data as currently presented. For example, some prematures may indeed be advanced in many areas of behavioral and neurophysiological development, but this is counterbalanced by prematures who are significantly delayed in these parameters for medical reasons such as hypoxia or metabolic disturbance, while a third portion of the infants has uneven and disorganizing mixtures of delayed and advanced development in selective modalities. Hopefully future research which takes these various possibilities into consideration will give us a better understanding of this complex problem.