title: Sources of error in the Piagetian water-level task.
abstract: Task materials were devised which allowed two different explanations of the Piagetian water-level task to be distinguished. Two experiments are reported with 5-6 and 7-8 year olds in which both a predictive and a perceptual task were used. The results support Ibbotson and Bryant's explanation that the performance of young children is affected by a perpendicular bias. This effect was weaker, particularly among 7-8 year olds, in the perceptual task.
authors.affiliation: Department of Psychology, University of York, Heslington, UK.
authors.forename: D
authors.initials: D
authors.lastname: Sommerville
authors.forename: M V
authors.initials: MV
authors.lastname: Cox
mesh_terms: D001288:Attention; D002648:Child; D002657:Child Development; D002675:Child, Preschool; D003210:Concept Formation; D003463:Cues; D005556:Form Perception; D006801:Humans; D009949:Orientation; D013028:Space Perception