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The Psychometrics Centre

Cambridge Judge Business School

The Wechsler Objective Numerical Dimensions (WOND) is a test of numerical ability in children that can be used in the diagnosis of special educational need, in particular, dyscalcia. 

Following the success of WORD (the Wechsler Objective Reading Dimensions) as an assessment of dyslexia in the UK, The Psychological Corporation asked us to investigate the other 5 subtests of the US based Wechsler Individual Achievement Test (WIAT) and to consider whether they, too, could be adapted and standardised for the UK.

The introduction of WIAT in the US arose following specific US legislation requiring the ability level of a child to be taken into account when making a diagnosis of learning difficulties. It was believed that diagnosis based purely on a child's academic performance in school was insufficient. WIAT was designed as a companion test to the Wechsler Intelligence Scale for Children (WISC), and included subtests of Basic Reading, Reading Comprehension, Numerical Operations, Mathematical Reasoning, Oral Expression, Listening Comprehension, Writing and Spelling.

The Subtests included in WOND were

  • Numerical Operations
  • Mathematical Reasoning

These two subtests were administered to a sample of around 400 children throughout the UK on the basis of a stratified sample according to national demographics available from the Government. This enabled the development of national norms, enabling a child’s score at a particular age to be compared with that of other children of the same age.

When administered alongside a general ability test such as the Wechsler Intelligence Scale for Children (WISC), a comparison of the child’s numeracy score with that would be expected for someone of his/her age and ability provides the basic data by which an educational psychologist or other assessment professional can provide a diagnosis of dyscalcia.

WOND, together with its companion tests WOLD and WORD, have now been superseded by WIAT-II. For more information contact Pearson Assessment at their offices in London.

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