Abstract copyright UK Data Service and data collection copyright owner.

Developmental disorders of arithmetical ability are frequently seen in children of normal intelligence who have no known medical history of relevance. A recent study reports an incidence of 4%. Three forms of the disorder have previously been identified, relevant to the structure of the underlying cognitive system. One of these involves disproportionate difficulty in the acquisition of arithmetical facts and tables. This project addresses several questions emerging from cognitive psychology, regarding fact retrieval, which can be addressed by studying those with selective difficulties. The specific aims and objectives of the study were : to determine whether fact retrieval seems to be an automated system devoid of semantic activation; to determine whether quality of fact retrieval is related to speed of counting and/or short term memory span; to determine whether there is delayed speed of access to arithmetical facts in those with number fact disorders; to determine whether spatial dyscalculia is evident among children with developmental disorders of arithmetic, including those with spatial problems in non-arithmetical systems; to conduct an exploratory investigation of the developmental arithmetical disorder seen in William's Syndrome.

Main Topics:

The dataset contains the results from testing the normal children, the children with Turner's Syndrome, the children with number fact developmental dyscalculia and the children with William's Syndrome on a range of psychological measures. The measures relate to abilities in arithmetic, short term memory, counting, speed of speech, knowledge and speed of recall of automated sequences and speed of naming.

Purposive selection/case studies

William's Syndrome cases : all available in area;Turner's Syndrome cases : selected by date of

Face-to-face interview

Psychological measurements