Tittemore J A, Lawson J S, Inglis J
J Child Psychol Psychiatry. 1987 Jan;28(1):173-80. doi: 10.1111/j.1469-7610.1987.tb00661.x.
A learning disability index (LDI) based on a principal components analysis of the WISC-R normative data has been developed to depict verbal or nonverbal deficits on that test. This index was calculated for the individual test performance of a total of 1371 children referred to a school-board psychology service because of educational difficulties. These children, categorised by sex and age, returned mean scores on this index that were reliably different from the scores of the normative population only after the age of 8 years in the case of the boys, and 7 years in the girls. This cross-sectional age effect was confirmed by longitudinal data obtained from the test-retest scores of a subset of these children.
基于韦氏儿童智力量表修订版（WISC - R）常模数据的主成分分析开发了一种学习障碍指数（LDI），以描述该测试中的语言或非语言缺陷。对因教育困难被转介到学校董事会心理服务部门的总共1371名儿童的个体测试成绩计算了该指数。这些按性别和年龄分类的儿童，该指数的平均得分仅在男孩8岁、女孩7岁之后才与常模人群的得分有显著差异。从这些儿童的一个子集中获得的重测分数的纵向数据证实了这种横断面年龄效应。
