Psychometric Properties
- Internal consistency ranges from 0.80-0.98.
- Test-retest reliability ranges from 0.85-0.98.
WIAT–II has been empirically linked with the WISC–IV, the WPPSI–III, and the WAIS–III. These relationships provide valid discrepancy scores to allow comparisons between achievement and ability. The WIAT-II UK was standardised between 2003-2004 as part of the WISC-IV standardisation with 892 individuals aged 4-16years 11 months (US norms are available up to age 85). The UK project was conducted at City University by Professor John Rust and Professor Susan Golombok. The WAIT-II standardisation also includes several special group studies including those with learning difficulties, ADHD, emotional disturbance, hearing impairments, speech and language impairments and those who are classed as gifted.
The WIAT-III US was standardised on 3,000 students and adults aged 4-19:11. Linking studies were carried out with the WAIS-IV, WISC-IV, WPPSI-III, WMV, and DAS-II with correlations ranging from .60-.82. Special group studies include those with learning difficulties in reading, writing and math, expressive language disorder and mild intellectual difficulties.
Read more about this topic: Wechsler Individual Achievement Test
Famous quotes containing the word properties:
“A drop of water has the properties of the sea, but cannot exhibit a storm. There is beauty of a concert, as well as of a flute; strength of a host, as well as of a hero.”
—Ralph Waldo Emerson (1803–1882)