“…Nonetheless it is probably inappropriate to consider the extension of pre-school experience as retention or repetition; this option might more properly be classified as preventive intervention and its effects considered within the literature on that topic. Recent reports on the effects of preventive programs indicate generally positive outcomes, particularly when parents are well-informed and participate in the delivery of services (Baloghova-Polkorabova, 1983;Dunst, 1983;Reynolds et al, 1983;Sparrow et al, 1983;Bailey & Bricker, 1984;Clarke, 1984;Goodman et al, 1984;Ramey et al, 1984;Reader, 1984;Seitz et al, 1985). To date, however, no definitive explanations have emerged to account for reported developmental gains; curriculum content, parent-infant interaction, parental involvement in decision-making and social/ecological systems have all been implicated.…”