title: A puzzle form of a non-verbal intelligence test gives significantly higher performance measures in children with severe intellectual disability.
abstract: BACKGROUND
  Assessment of 'potential intellectual ability' of children with severe intellectual disability (ID) is limited, as current tests designed for normal children do not maintain their interest. Thus a manual puzzle version of the Raven's Coloured Progressive Matrices (RCPM) was devised to appeal to the attentional and sensory preferences and language limitations of children with ID. It was hypothesized that performance on the book and manual puzzle forms would not differ for typically developing children but that children with ID would perform better on the puzzle form.
  
  
  METHODS
  The first study assessed the validity of this puzzle form of the RCPM for 76 typically developing children in a test-retest crossover design, with a 3 week interval between tests. A second study tested performance and completion rate for the puzzle form compared to the book form in a sample of 164 children with ID.
  
  
  RESULTS
  In the first study, no significant difference was found between performance on the puzzle and book forms in typically developing children, irrespective of the order of completion. The second study demonstrated a significantly higher performance and completion rate for the puzzle form compared to the book form in the ID population.
  
  
  CONCLUSIONS
  Similar performance on book and puzzle forms of the RCPM by typically developing children suggests that both forms measure the same construct. These findings suggest that the puzzle form does not require greater cognitive ability but demands sensory-motor attention and limits distraction in children with severe ID. Thus, we suggest the puzzle form of the RCPM is a more reliable measure of the non-verbal mentation of children with severe ID than the book form.
authors.affiliation: Brain Sciences Institute, Swinburne University, Hawthorn, 3122, Australia . katrinabello@hotmail.com
authors.forename: Katrina D
authors.initials: KD
authors.lastname: Bello
authors.forename: Nahal
authors.initials: N
authors.lastname: Goharpey
authors.forename: Sheila G
authors.initials: SG
authors.lastname: Crewther
authors.forename: David P
authors.initials: DP
authors.lastname: Crewther
mesh_terms: D001288:Attention / Q000502:physiology; D001321:Autistic Disorder / Q000175:diagnosis / Q000523:psychology; D002648:Child; D002675:Child, Preschool; D003072:Cognition Disorders / Q000175:diagnosis / Q000523:psychology*; D018592:Cross-Over Studies; D004314:Down Syndrome / Q000175:diagnosis / Q000523:psychology; D005260:Female; D005556:Form Perception / Q000502:physiology*; D006801:Humans; D008607:Intellectual Disability / Q000175:diagnosis / Q000523:psychology*; D007361:Intelligence Tests / Q000706:statistics & numerical data*; D007807:Language Tests / Q000706:statistics & numerical data; D008297:Male; D009483:Neuropsychological Tests / Q000706:statistics & numerical data; D012016:Reference Values; D014705:Verbal Behavior / Q000502:physiology