The Persian Handwriting Assessment Tool for Primary School-Aged Children: Further Validation.

Background: Handwriting problems are one of the common problems among students in the early years of education. The current study aimed to determine further validation aspects of the Persian Handwriting Assessment Tool (PHAT) in primary school-aged children.

Methods: The current methodological study was conducted on 452 healthy 8-10-year-old students in Tehran, Iran, selected via random cluster sampling method. Inclusion criteria were native Persian-speaking and no documented physical and mental impairments. Construct and structural validities were established by exploratory factor analysis (EFA) using principal axis factoring with Promax rotation and confirmatory factor analysis (CFA), respectively. Criterion validity was examined by expert opinion as the gold standard using Pearson correlation test. Internal consistency, test-retest, and inter-rater reliability were examined using Cronbach's alpha and intra-class correlation (ICC). Test-retest had a seven-day interval.

Results: The EFA results indicated two separate factors in the copying and dictation domains. Speed and orthographic error and size were considered as separate items. The CFA confirmed the factor structure. Criterion validity revealed low to moderate correlation (formation: 0.548, P<0.001; 0.503, P<0.001, spacing: 0.553, P<0.001; 0.307, P=0.030, alignment: 0.442, P<0.001; 0.358, P=0.011, size: -0.376, P=0.007; -0.445, P<0.001, and slant: 0.360, P=0.010; 0.372, P=0.008) in copying and dictation domain, respectively. Acceptable internal consistency (Cronbach's alpha: 0.72-0.99), excellent test-retest (ICC: 0.76-0.99), excellent inter-rater reliability between teachers (ICC: 0.86-0.95), and good to excellent inter-rater reliability between teachers and the occupational therapist (ICC: 0.60-0.95) were reported.

Conclusion: The results indicated that the PHAT was a valid and reliable tool for assessing handwriting in primary school-aged children.