Validation of the PLI Inventory as a Screening Measure of Procedural-non verbal Learning Difficulties

Abstract

The IDAP (PLI) Inventory is presented as a screening test for procedural learning difficulties. 190 participants aged 6-12 years with normal intelligence: 95 from the control group and 95 from the clinical groups: procedural-nonverbal learning disorder (n=53) and ADHD (n=42). Exploratory (KMO=0.71 and MSA=0.52-0.87) and confirmatory (CMIN/DF=2.4; TLI=0.985; CFI=0.961 and RMSEA=0.059) factor analyses were performed. We reduced to 24 items and obtained 6 factors that explain 70.6% of the total variance: motor skills, motor coordination, language, pragmatics, school learning and socioemotional. Validity and reliability are tested and descriptive statistics are provided. In all factors, except language, the TAP group (U-Mann Whitney) differs from the control group (p=.001) and the ADHD group (p=.005). The sensitivity and specificity of the test are demonstrated. Discriminant analyses indicate that it allows us to correctly classify 96.4% of our caseload. The scoring criteria are provided. This new assessment tool provides relevant information for guidance and educational psychology professionals in the detection of procedural learning difficulties and in the differential diagnosis, as well as for the subsequent design of a more precise and effective educational psychology intervention.