This study examined the effect of presentation rate on accuracy of digit serial recall and on serial position curves of digit strings of different lengths with 18 boys classified as reading retarded and a comparison group of children (ages for both groups averaged 11 years) who read at grade level. The results indicated that normal children recalled significantly more digit strings than did the reading retarded children, but that the effect of rate was different for the two groups of children. The average number of strings correctly recalled increased linearly with an increase in rate for the reading retarded group, but the normal group did best at both the fast and the slow rates. An examination of the serial position curves for both groups revealed that while the curves of the normal children maintained the primacy effect across the different rates of presentation, the curves of the reading retarded children showed a lack of a primacy effect at slow rates and an increase in the primacy effect at the fast rate. (Author/PHR)