Lewis C, Hitch G J, Walker P
Department of Psychology, University of Lancaster, U.K.
J Child Psychol Psychiatry. 1994 Feb;35(2):283-92. doi: 10.1111/j.1469-7610.1994.tb01162.x.
Data from an epidemiological sample (n = 1206) of British schoolchildren were used to estimate the proportions of 9- to 10-year-olds with specific arithmetic difficulties (SAD), combined with arithmetic-and-reading difficulties (ARD), and specific reading difficulties (SRD). Children in the sample contributed scores on separate tests of arithmetic, reading and nonverbal intelligence. Using a cutting-score approach, which took into account performance on all three tests, a small group of children with SAD (1.3%) were distinguished from larger groups with ARD (2.3%) and SRD (3.9%). Contrary to some previous reports, there were equal numbers of males and females within each of the two groups with arithmetic difficulties but a preponderance of males over females amongst the group with specific reading difficulties.
来自英国学童流行病学样本（n = 1206）的数据被用于估计9至10岁有特定算术困难（SAD）、合并算术和阅读困难（ARD）以及特定阅读困难（SRD）的儿童比例。样本中的儿童提供了算术、阅读和非言语智力的单独测试分数。采用考虑所有三项测试表现的切割分数方法，一小群有SAD的儿童（1.3%）与有ARD的较大群体（2.3%）和SRD的群体（3.9%）区分开来。与之前的一些报告相反，在有算术困难的两组中，男性和女性数量相等，但在有特定阅读困难的群体中，男性多于女性。
