Scale for developmental dyslexia screening: evidence of validity and reliability

Area of Science:

• Educational Psychology
• Developmental Psychology
• Special Education

Background:

• Early identification of developmental dyslexia (DD) is crucial for timely intervention.
• Existing screening tools may require further validation for use by elementary school teachers.

Purpose of the Study:

• To evaluate the empirical validity and reliability of a teacher-administered screener for developmental dyslexia risk.
• To establish the psychometric properties of the proposed screening scale.

Main Methods:

• A scale was administered by 12 teachers to 95 third-grade students.
• Student performance on reading and writing tasks was assessed.
• Statistical analyses included factor analysis, internal consistency, item response theory (IRT), correlation with external variables, and temporal stability.

Main Results:

• The scale demonstrated strong internal consistency and a single-factor structure.
• Item response theory analysis confirmed items measure a single construct.
• Moderate correlations were found between scale items and external reading/writing measures.
• Temporal stability of teacher evaluations was confirmed.

Conclusions:

• The study provides evidence for the validity and reliability of the developmental dyslexia screener.
• The screener can be effectively used by elementary teachers for identifying at-risk students.
• Approximately 9% of students were identified as at-risk, aligning with known dyslexia prevalence.