Reliability and Validity of the Writing Essential Skill Screener — Preschool Version (WESS-P)

Internal consistency, test-retest reliability, item analysis, and construct and concurrent criterion-related validity of the Writing Essential Skill Screener — Preschool Version (WESS-P) were studied using four independent samples of boys and girls, ages 4 through 5. Median item difficulty was.65 and median item discrimination was.84 for the standardization sample. A decision reliability study resulted in accurate decisions being made for 92% of a sample of children with and without pre-writing skill deficiencies. A one-factor principal component solution was derived. Internal consistency was.95 and.93, whereas 30-day test-retest reliability was.91. The WESS-P yielded concurrent cirterion-related validity coefficients of.85 with the Test of Early Written Language (TEWL), and.82 with the Developmental Test of Visual-Motor Integration (VMI), and accurately identified 92% of participants in a diagnostic validity study. The WESS-P displayed a high degree of reliability and validity for a brief pre-writing skills screener. Implications for policy and practice were discussed.