Has the Perceptual Deficit Hypothesis Led Us Astray?

Vellutino, Frank R.; Steger, Barbara M.; Moyer, Sara C.; Harding, Constance J.; Niles, Jerome A.

doi:10.1177/002221947701000614

Cited by 82 publications

(33 citation statements)

References 28 publications

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“…Young children may have had difficulties putting their pencils exactly at the position they planned due to not fully developed motor skills. Although several studies (e.g., Vellutino, Steger, Moyer, Harding, & Niles, 1977) did not find support for this motor deficit hypothesis, the test leaders' observations in the present study mentioned some important differences in motor skills, which may have introduced nuisance in the observed estimation locations of young children.…”

Section: Discussioncontrasting

confidence: 91%

Multiple Representations in Number Line Estimation: A Developmental Shift or Classes of Representations?

Bouwmeester

Verkoeijen

2012

Cognition and Instruction

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Children's estimation patterns on a number line estimation task may provide information about the mental representation of the magnitude of numbers. Siegler and his colleagues concluded that children's mental representations shift from a logarithmic-ruler representation to a linear-ruler representation. However, there are important methodological issues with respect to their number-line studies that threaten the validity of the conclusions. We discuss these methodological issues and propose an alternative method to analyze estimation data. One hundred nineteen children from kindergarten, first, and second grade performed a number-line estimation task in which they had to estimate the position of 30 numbers on a 0-to-100 number line. The results supported the hypothesis that children show various kinds of estimation patterns. Five classes of children were distinguished, which were characterized by different estimation patterns. A remarkable result was that the logarithmic-ruler representation was not found. Although young children were more likely to show overestimation of small numbers than older children, this developmental trend was small and not significant.Most people are unaware of how many times they actually estimate in everyday life. We estimate at what time we have to leave home in order to catch the bus, we estimate whether we have enough cash to pay for our groceries, we estimate the amount of salt we add to our meal to make it tasty yet not too salty. For these and many other examples estimation is used because accurate estimates are sufficient for many purposes and because people often lack the knowledge, time, means, or motivation needed to calculate precise values (Siegler & Booth, 2005). However, estimation in everyday life is a very complex process because to be of practical use it may require knowledge of the problem context, knowledge of measurement units like time, distance, quantity (Siegler & Booth, 2004) and a good awareness of the boundaries of an estimate.Despite the fact that people often use estimation in their day-to-day routine, estimation hasuntil recently-not explicitly been taught in elementary school. However, this may not be problematic, because various studies have demonstrated that estimation performance is related to general arithmetic skills, which do receive a lot of attention in elementary school instruction.

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Section: Discussioncontrasting

confidence: 91%

Multiple Representations in Number Line Estimation: A Developmental Shift or Classes of Representations?

Bouwmeester

Verkoeijen

2012

Cognition and Instruction

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“…In this case reading rate becomes a measure of fluency-a dynamic rapid visual-processing task. So whilst Vellutino suggested that theories of visual deficits were lacking theoretical foundation, and were unlikely to explain reading disability operationally at that time (Vellutino et al, 1977), more recent advances in understandings of the visual system have provided researchers with a more specific theoretical basis for the role of visual processing and visual attention in dyslexia.…”

Section: Visual Deficitsmentioning

confidence: 99%

Towards an understanding of the role of the ‘magnocellular advantage’ in fluent reading

Laycock

Crewther

2008

Neuroscience & Biobehavioral Reviews

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“…The majority of such research focuses on how visual skill might enhance reading skill, and these results are quite mixed across orthographies. There is general agreement that pure visual skill is not likely a core cause of reading across orthographies (e.g., Goswami, 2004;Vellutino, Steger, Moyer, Harding, & Niles, 1977).…”

Section: Introductionmentioning

confidence: 99%