The Ranschburg effect is an inhibitory effect on recall observed when a string of items, which has been presented for immediate recall, contains a repeated element. A review of extant research suggests that differential error rates for the repeated elements occur when: (a) the series of items to be remembered is at, or just beyond, span-length, (b) there is only one repetition of only one of the items of the series, (c) items are presented sequentially and the occurrences of the repeated element are separated by two or more different elements, (d) the repeated items do not occupy distinctive positions in the series, (e) the S is to order items in recall as in presentation, and (f) recall is immediate or only very briefly delayed. To account for errors on repeated elements, it was suggested that the repeated element, although readily available for recall, is not emitted the appropriate number of times. One encoding and two memorial mechanisms (namely, a failure to detect repetition, a failure to remember the repetition structure of the string, and a failure to remember which was the repeated item) logically may contribute to the effect when strings contain only one repetition of only one of the items. When an item is repeated more than once, or when more than one item is repeated, a fourth mechanism concerned with the encoding of number of repetitions may become increasingly important. Existing and new research was used to begin to test the adequacy of these explanatory mechanisms. (Author).