Purpose of the Questionnaire

The WISC-III is the Greek adaptation of the Wechsler Intelligence Scale for Children and is used for the comprehensive assessment of the cognitive functioning of children aged 6–16 years. It is addressed to clinical psychologists, educational psychologists, and specialists for the diagnosis of learning difficulties, developmental disorders, and the identification of cognitive abilities. It measures general intelligence (FSIQ) and provides information on specific cognitive functions.

Questionnaire Analysis

The test was developed by David Wechsler (1991) and was adapted for the Greek population by research teams. It includes 13 subtests organized into two main scales: the Verbal Scale (VIQ), which assesses verbal skills, cognitive flexibility, and crystallized knowledge; and the Performance Scale (PIQ), which measures visuomotor skills, processing speed, and visuospatial reasoning. Each subtest provides specific information about different cognitive functions.

Scoring of Questions

Raw scores are converted into standardized scores (M=10, SD=3 for subtests, M=100, SD=15 for scales). The final score includes the Full Scale IQ (FSIQ), the Verbal IQ (VIQ), the Performance IQ (PIQ), and specific indices for each subtest.

Statistical Analysis

The Greek adaptation has been standardized on a representative sample of Greek-speaking children. Statistical indices show internal consistency (α > 0.85 for all scales), test-retest reliability (r = 0.80–0.90), and correlations with other intelligence measures (r = 0.70–0.85).

Validity of the Questionnaire

The validity of the WISC-III has been confirmed through correlational studies with other intelligence tools, discriminant ability between diagnostic groups, and comparison with the international version of the test.

Reliability of the Questionnaire

The tool shows high reliability with internal consistency (α > 0.85), test-retest stability (r > 0.80), and inter-rater agreement (>90%).

Bibliography

Foreign Literature
Wechsler, D. (1991). WISC-III: Wechsler Intelligence Scale for Children – Third Edition Manual. Pearson Assessment.
Greek Literature
Official Greek adaptation: Available through university research centers
Keywords
Intelligence, cognitive assessment, WISC, IQ, learning difficulties, developmental disorders, psychometric tools.