Middle Eastern Journal of Disability Studies

Abstract
Background & Objectives: Learning disabilities are currently the largest group of disabilities in special education. These disabilities are defined as impairments in one or more basic psychological processes, including the comprehension or use of spoken or written language, which may manifest as impairments in listening, thinking, reading, writing, speaking, spelling, and mathematical calculations. In the context of learning disabilities evaluation, one of the few diagnostic–prescriptive tools is the fourth edition of the Learning Disability Evaluation Scale (McCarney and House, 2018), which, in addition to its diagnostic application, provides suggestions for relevant interventions, leads to an individualized educational plan. The provided interventions are based on the seven–component theoretical structure of this scale with a logical combination. The present study was conducted to validate the seven–component structure of the Diagnostic and Prescriptive Learning Disability Evaluation Scale (McCarney & House, 2018) among the second– to fifth–grade elementary students.
Methods: This research was a descriptive–analytical study of tool development type. The statistical population of the research consisted of the second– to fifth–grade elementary students in the 2021–2022 academic year. According to the announcement of the cooperation of elementary school principals, Tehran, Mazandaran, and Lorestan provinces were selected as the study settings using the available sampling method. Then, in each of these provinces, cities, elementary schools, and learning disability centers were selected using the available sampling method. Finally, following the minimum required sample size according to Mayers (2013) and considering the inclusion and exclusion criteria, the standard sample group of 298 students (145 girls and 153 boys) was selected by simple random and purposeful sampling method by the teachers of selected schools. Also, the clinical sample group of 27 students (9 girls and 18 boys) with learning disabilities was selected using the available sampling method by the educators of the selected learning disability centers. This study was conducted to validate the fourth edition of the Diagnostic–Prescriptive Learning Disability Evaluation scale (LDES–4) (McCarney & House, 2018). To adapt this scale to Persian culture and language based on the method presented by the World Health Organization in 2006, the following steps were performed: direct translation, referral to an expert panel and back translation, obtaining cognitive information through clinical interviews, and at last compiling the final version and documenting. The Colorado Learning Difficulties Questionnaire (Willcutt et al., 2011) was used to explore concurrent validity. To determine the content validity, the content validity ratio (CVR) and content validity index (CVI) were calculated using the opinions of 6 professors and experts in learning disabilities. To probe the construct validity, confirmatory factor analysis was utilized using the maximum likelihood estimation method in AMOS26. Internal consistency was also investigated using the Cronbach alpha method, and temporal stability was assessed using the test–retest reliability method with a time interval of four weeks in the clinical sample group using the intraclass correlation coefficient. The Pearson correlation coefficient was calculated for the clinical sample group for concurrent validity. In addition, to check the discriminant validity, 27 students of the normal sample group, who were equal to the clinical sample group (27 people) in terms of gender, educational level, and place of residence, were selected randomly, and their scores were compared with the scores of the clinical sample group through the independent t test. In this study, to perform the confirmatory factor analysis, AMOS26 software was used, and the rest of the statistical analyses were performed using SPSS26 at a significance level of 0.05.
Results: In the confirmatory factor analysis using the item parceling modifying method, the fit indices were CMIN/df=3.883, CFI=0.963, PCFI=0.770, PNFI=0.761, and IFI=0.963, indicating the desired fitness of the seven–component structure of the Diagnostic–Prescriptive Learning Disability Evaluation Scale with the data. In examining the discriminant validity, there was a significant difference between the normal and clinical groups regarding the scale's total score (p<0.001). The Cronbach alpha value for the whole scale was 0.94, and each component was calculated at more than 0.70. Also, the intraclass correlation coefficients, with a confidence interval of 95% for the whole scale and its seven components, ranged from 0.891 to 0.970, which was significant (p<0.001), indicating the appropriate temporal stability of the scale. Also, a positive and significant relationship was obtained between this scale's total score and the Colorado Learning Difficulties Questionnaire (p<0.05).
Conclusion: According to the findings, the fourth edition of the Diagnostic–Prescriptive Learning Disability Evaluation scale (LDES–4) with a seven–component structure can be used as a valid and reliable tool to assess learning disabilities in the second– to fifth–grade elementary students.