Improved Age Appropriateness
WPPSI™-III has undergone substantial revision to increase the scale's age appropriate properties.
- Age range has been lowered to 2 years 6 months, allowing for earlier testing of children who could benefit from earlier intervention with special services
- Scale has been divided into two age bands, 2:6-3:11 years and 4:0-7:3 years
- Younger children take fewer subtests that are designed to measure verbal comprehension and perceptual organization abilities
- Older children take a greater number of subtests designed to measure verbal comprehension, perceptual organization, and processing speed abilities
- Less emphasis on acquired knowledge
- Instructions to children have been simplified
- Elimination of time bonuses due to the normal lags in motor skill development relative to cognitive skills
- Use of queries and prompts is generally unrestricted
- All stimulus booklet art has been redrawn to be more colorful and more closely resemble illustrations found in materials familiar to children
WPPSI™-III test materials have been modified to make administration of the scale as user friendly as possible.
- Instructions to the examiner and scoring procedures have been simplified
- New stimulus booklet page layout provides greater comfort and efficiency throughout testing
- Elimination of Object Assembly shield makes presentation of puzzle pieces less difficult and time-consuming
- All subtests now feature teaching and practice items
- Overall testing time for core subtests has been reduced, especially for children in the younger age group, with 25-35 minutes required for them and 40-50 minutes required for the older children
Improved Psychometric Properties
The scale's psychometric properties have significantly improved.
- New items have been added to ensure that all existing subtests have adequate floors, ceilings, and difficulty-level gradients
- All items have been reviewed for ethnic, gender, regional, and socio-economic bias
- Seven new subtests were developed to enhance the scale's measurement capabilities of fluid reasoning, receptive and expressive vocabulary, and processing speed
- Significantly improved reliability and validity
- Norms include Subtest Scaled Score and Composite Scores (e.g. FSIQ, VIQ, PIQ, PSQ)
Validity Studies Enhance WPPSITM-III's Clinical Value
Data from the WPPSITM-III validity studies allow a better understanding of the relative performance of clinical and non-clinical groups, while giving the examiner a better way to describe a child's individual performance relative to his or her appropriate reference group.
- Additional clinical studies using groups include mental retardation (mild and moderate severity), developmental delay, attention deficit/hyperactivity disorder, cognitively gifted, autistic, expressive language disorder, mixed receptive/ expressive language disorder, and at risk for developmental delay
- Additional validity studies linked the WPPSI™-III to the Adaptive Behavior Assessment System™ (ABAS™), the Wechsler Individual Achievement Test®-Second Edition (WIAT®-II), and the Differential Ability Scales® (DAS®) are added to reflect the IDEA Part C legislation which recommends the use of multiple diagnostic criteria for identification of children for special services
- All revisions were driven by an advisory panel of experts, extensive literature review, customer, and examiner feedback, and additional professional expert reviewers