A study tested the theory that an item that stands out from its background is better remembered than one that is similar to the background (the isolation effect). Specifically, the study examined whether the isolation effect would be greater when there was a larger and more confusing mass of background items, whether position of the isolated item would enhance memory for it and its surrounding items, and whether varying its position in a list would affect memory. Subjects, 44 college students, were presented with 12 lists of consonants on an overhead projector. Isolation of items was achieved by printing them slightly larger than other items on the lists. ANOVA was used to assess the number of list items and the number of isolated items each subject recalled. The factors analyzed were (1) type of isolate; (2) scoring (letters correct only if in correct position--strict scoring--and letters correct if recalled in any position--lenient scoring); (3) list length (9, 11, and 13 items); and (4) isolation (isolated and unisolated trigrams). Results showed that the isolation effect was in evidence and, at least for lenient scoring procedures, support the theory that the effect increased with increases in list length. This theory was not supported with strict scoring procedures, however. The findings suggest that isolation of an item improves item memory in proportion to its list length or weakness, but not position. (FL)