Test-Retest Reliability and Practice Effect with the Shipley-Institute of Living Scale

Upon re-testing with Shipley S-ILS (3 mo., 56 Ss), reliability coefficients are: Verbal, .77; Abstract, .63; Conceptual Quotient, .57; and Intelligence Quotient, .74 (all ps < .01). These coefficients and the pattern of mean-score increases suggest that the S-ILS is a “weak” measure of intellectual deterioration but a “better” measure of intellectual functioning.