title: A methodological study of the Shipley Institute of Living Scale in alcoholics and non-alcoholics: reliability, discriminating items and alternate forms.
abstract: In Study 1, 430 sober male alcoholics and 98 nonalcoholics completed the Shipley Institute of Living-Vocabulary (SILS-V) and Abstraction (SILS-A) under the standard instructions. Alcoholics performed significantly more poorly than the nonalcoholics on SILS-A. High test-retest reliability of the SILS with a 2-week interval between testings was obtained. Item analysis of the 20-item SILS-A revealed that only items 4-14 discriminated alcoholics and controls, six items required reversal of a cognitive set (reversal) and five did not (nonreversal items). Exploratory factor analyses confirmed essentially the same division of items. In Study 2, two 10-item forms of SILS-A equated for difficulty level and reversal-nonreversal cognitive demands were administered to 186 male and female college students. Results indicate the two forms are equivalent in difficulty, demonstrate no gender differences and correlate significantly with cumulative college grade point averages.
authors.affiliation: Center for Alcohol and Drug-Related Studies, Department of Psychiatry and Behavioral Sciences, University of Oklahoma Health Sciences Center, Oklahoma City, Oklahoma 73104, USA.
authors.forename: S J
authors.initials: SJ
authors.lastname: Nixon
authors.forename: O A
authors.initials: OA
authors.lastname: Parsons
authors.forename: K W
authors.initials: KW
authors.lastname: Schaeffer
authors.forename: R L
authors.initials: RL
authors.lastname: Hale