S L Hartley1, W E MacLean. 1. Department of Psychology, University of Wyoming, Laramie, Wyoming 82071, USA. shartley@uwyo.edu
Abstract
BACKGROUND: Likert-type scales are increasingly being used among people with intellectual disability (ID). These scales offer an efficient method for capturing a wide range of variance in self-reported attitudes and behaviours. This review is an attempt to evaluate the reliability and validity of Likert-type scales in people with ID. METHODS: Fifty-one studies reporting response rates, response bias, reliability and validity of Likert-type scales among adolescents and adults with ID were reviewed. RESULTS: Low response rates were found among adolescents and adults with moderate to profound ID, when pictorial representations of response alternatives were not employed, and for Likert-type scales with self-descriptive statements. Response bias was evident, particularly among adolescents and adults with moderate to profound ID. Likert-type scales have better reliability and validity among adolescents and adults with borderline IQ or mild ID. Pretests and clarifying questions increase reliability and validity. CONCLUSIONS: Likert-type scales should include pictorial representations of response alternatives, a single set of one or two word response descriptors, clarifying questions, and pretests, and are best used with adolescents and adults with borderline IQ to mild ID.
BACKGROUND: Likert-type scales are increasingly being used among people with intellectual disability (ID). These scales offer an efficient method for capturing a wide range of variance in self-reported attitudes and behaviours. This review is an attempt to evaluate the reliability and validity of Likert-type scales in people with ID. METHODS: Fifty-one studies reporting response rates, response bias, reliability and validity of Likert-type scales among adolescents and adults with ID were reviewed. RESULTS: Low response rates were found among adolescents and adults with moderate to profound ID, when pictorial representations of response alternatives were not employed, and for Likert-type scales with self-descriptive statements. Response bias was evident, particularly among adolescents and adults with moderate to profound ID. Likert-type scales have better reliability and validity among adolescents and adults with borderline IQ or mild ID. Pretests and clarifying questions increase reliability and validity. CONCLUSIONS: Likert-type scales should include pictorial representations of response alternatives, a single set of one or two word response descriptors, clarifying questions, and pretests, and are best used with adolescents and adults with borderline IQ to mild ID.
Authors: Emily Shea Tanis; Susan Palmer; Michael Wehmeyer; Daniel K Davies; Steven E Stock; Kathy Lobb; Barbara Bishop Journal: Intellect Dev Disabil Date: 2012-02
Authors: Sigan L Hartley; Anna J Esbensen; Rebecca Shalev; Lori B Vincent; Iulia Mihaila; Paige Bussanich Journal: J Ment Health Res Intellect Disabil Date: 2015-04-06