A study investigated connections between reading difficulties and short term memory processes in order to explore the psychological basis for some individual differences in reading comprehension skills. Drawing on previous research indicating that poor readers were inferior to normal ones in judging whether two patterns of long and short tones were the same, the study examined whether the groups differed in ability to accurately encode patterns into auditory short term memory or in ability to maintain patterns in memory after they have been stored. The study also investigated the relationship among performance on a verbal sequential memory task, auditory digit span, and reading skill. Subjects, 35 normal and 63 poor fifth grade readers, were presented with pairs of Morse Code-like patterns separated by 1-, 2-, 5-, and 10-second intervals, and asked to judge if the patterns were the same. Results showed that poor readers performed significantly worse on pattern comparison only at the longest interval, suggesting an inability to maintain properly encoded patterns and that poor retention of information in short term memory probably results in both semantic and syntactic processing breakdowns during reading. Digit span correlated significantly with reading ability, but not with pattern-comparison performance. Digit span may be correlated with reading skill because of a common dependency on rapid coding of verbal stimuli. (FL)