Validity of school history as a diagnostic criterion for reading disability

In order to assess the validity of school history information as a diagnostic criterion for reading disability, reading performance data from 304 children with a positive history for reading problems were compared to those from 319 children with a negative school history. These children are members of twin pairs who are participants in the Colorado Reading Project (DeFries 1985). A multivariate analysis of variance of Reading Recognition, Reading Comprehension, and Spelling subtest scores from the Peabody Individual Achievement Test (Dunn and Markwardt 1970) yielded a highly significant (p <0.001) difference between groups for both the multivariate and univariate comparisons. The difference between the unweighted mean scores of the school-history positive and negative groups for Reading Recognition was 2.1 standard deviations. Moreover, when discriminant weights estimated from an independent sample of 140 reading-disabled and 140 control nontwin children were used to reclassify the sample of twins, 75% of those with a positive history for reading problems were classified as being reading disabled and 95% of those with a negative history were classified as unaffected. Thus, results of this study establish the validity of school history information and suggest that such information may have considerable utility for ascertaining samples of reading-disabled children.     

Differential genetic etiology of reading disability as a function of mathematics performance

In order to assess the etiology of reading disability as a function of mathematics performance, data from 168 monozygotic (MZ) and 127 same-sex dizygotic (DZ) twin pairs in which at least one member of each pair was reading-disabled were subjected to quantitative genetic analyses. MZ and DZ concordance rates for reading disability were computed for different levels of mathematics performance, and reading performance data were fitted to an extension of the basic multiple regression model for the analysis of selected twin data. Results of these analyses suggest that genetic factors may be especially salient as a cause of reading disability in children with borderline deficits in mathematics performance: thus, mathematics performance may be a valid dimension for diagnosing subtypes of reading disability.     

Identifying sex differences in reading disability

The issue of sex differences in reading disability has been of recent interest in relation to sex ratios in families with reading disabled children and to possible sex biases in referred populations. Data from a study of 570 twins are used to develop alternative definitions of reading disability that vary in the manner to which sex effects are taken into account. These definitions include discrepancies between reading quotients and IQ, the use of the regression of reading onto IQ and chronological age/reading age differences. In each case the reading and spelling disability was defined either separately for the sexes or based upon the data for the sexes combined and with and without an IQ>90 exclusion criterion. The consequences of using the alternative definitions for prevalence, sex ratio and heritability are examined. The results demonstrate that the characteristics of reading disabled children vary with the way disability is defined. The excess of males seems to be a robust finding. Definitions that take into account differences in mean score for males and females reduce but do not eradicate the sex ratio. From the genetic analysis, there is no support for the suggestion that the genetic effect on reading is greater for females than males. It is concluded that the use of regression based procedures for identifying reading disability is desirable but that at present there is insufficient evidence to justify the adoption of separate regression procedures for the two sexes.     

Genetic etiology of spelling deficits in the Colorado and London twin studies of reading disability

The basic multiple regression model for the analysis of selected twin data (DeFries and Fulker 1985, 1988) was fitted to spelling data from 100 pairs of MZ twins and 71 pairs of same-sex DZ twins tested in the Colorado Reading Project (DeFries, Olson, Pennington and Smith 1991), and to data from 12 pairs of MZ twins and 15 pairs of same-sex DZ twins tested in the London twin study of reading disability (Stevenson, Graham, Fredman and McLoughlin 1984, 1987). Estimates of h _g ² obtained from analyses of these data suggest that about 60% of the deficit of probands is due to heritable influences in both samples. When a regression model was fitted separately to data from males and females in the combined Colorado and London samples, resulting estimates of h _g ² were 0.66±0.18 and 0.56±0.19, respectively, a nonsignificant difference. Collaborative analyses of data from additional twin studies of reading disability would facilitate more rigorous tests of hypotheses of differential genetic etiology as a function of group membership.     

Early prediction of individual growth in reading

Seventy four boys with reading disabilities and amatched control group of normal readers were followedduring their compulsory schooling (to grade 9). Worddecoding performance was assessed with the Wordchainstest on three occasions. For each student a lineargrowth function was estimated. The slope parameter wasused as the dependent variable in a multipleregression analysis with a large number of explanatoryfactors from grades 2 and 3 including phonologicalskills, reading and spelling, non-verbal intelligence,motor skills, eye movements, teacher ratings of schoolbehaviour and parents' education. The proportion ofvariance in growth explained for the reading disabledboys amounted to 25%, the most powerful predictorsbeing early reading performance and non-verbalintelligence. More surprisingly, neither teacherratings nor family background gave useful predictiveinformation. For the control group none of theindependent variables explained the variance of growthin reading.     

The role of naming speed within a model of reading acquisition

That symbol naming speed is an importantcorrelate of reading skill has been generallyacknowledged. Just what contribution it makesand why is a much more difficult question. Wesuggest that the search for such answers isbest developed within a broad model of readingskill acquisition. We propose an informalmodel and review evidence for several of itslinks. The major lines of influence arehypothesized to flow from cognitive abilities(mediated by instructional factors) tointermediate and final reading outcomes. Theoutcomes at each level, however, are affectedby outcomes at other levels, and in other wayscombine to complicate the picture. Use of sucha model may focus our research questions morefinely and lead to a more preciseconceptualization of the basis for naming speed– reading relationships.     

Etiology of reading difficulties as a function of gender and severity

To test the hypothesis that the etiology of reading difficulties may differ for males and females in more severely impaired samples, reading performance data from monozygotic (MZ), same-sex dizygotic (DZ_ss), and opposite-sex dizygotic (DZ_os) twin pairs were analyzed using a model-fitting implementation of the DeFries-Fulker (DF) model (Purcell & Sham, 2003, Behavior genetics, 33, 271–278). Five non-independent samples were selected using cut-offs of −1 (N = 737 pairs), −1.5 (N = 654), −2 (N = 468), −2.5 (N = 335), and −3 (N = 198) standard deviations (s) below the mean composite reading score of control twins. Male/female gender ratios for children with reading difficulties were significantly higher than 1.0 for all five samples and increased as a function of severity (viz., 1.15, 1.17, 1.40, 1.61, and 1.88, respectively). When the DF model was fit to the data, estimates of heritability (h _g²) and shared environmental influences (c _g²) were not significantly different for males and females in any of the groups. Consequently, the most parsimonious model that provided a good fit to the data at all five levels of severity equated the heritabilities and shared environmental influences for males and females, and fixed the DZ_os coefficient of genetic relatedness at 0.5. Thus, these results provide no evidence for a differential etiology of reading difficulties as a function of gender in more severely impaired samples, and suggest that the same genetic and environmental influences contribute to reading difficulties in males and females, irrespective of severity.     

Promoting gains in reading fluency: a comparison of three approaches

On the ground that reading fluency entails appropriate phrasing or prosody as well as facile word recognition, we investigated the effectiveness of text-based and word-based repeated readings procedures for promoting fluency of reading aloud and comprehension in second-grade children. Repeated readings of text printed with spaces between phrases and ends of lines at clause boundaries (phrase-cued text), repeated readings of text printed with conventional layout (standard text), and repeated readings of lists of difficult words from text were compared. Computer-based, guided repeated reading training intervened between a pretest and post-test reading of text. Each training condition led to significant benefits on one or more of the experimental measures obtained from reading aloud. Repeated readings with text resulted in greater gains in fluency than repeated readings with word lists. Reading with natural prosody was most strongly facilitated by repeated readings of phrase-cued text, which provided visible support for sentence structure.

Phonological processes as predictors of specific reading skills in children at risk for reading failure

Children at risk for reading disability were evaluated as kindergartners and again as first graders to determine (1) intercorrelations among phonological processing tasks and (2) the relationship of such tasks to word identification and word attack. With IQ controlled, there were no intercorrelations among measures of phonological awareness, phonetic recoding in working memory, and phonological recoding in lexical access. Thus, these results failed to substantiate the concept of a general phonological processing ability. Partial correlations controlling for IQ revealed no relationship between reading and phonological awareness or phonetic recoding in working memory. In contrast, lexical access measures were significantly, albeit moderately, correlated with word identification but not word attack. Word attack and word identification were predicted by different combinations of variables. These results suggest that lexical access ability is an important factor in reading acquisition and that different combinations of phonological processes may be related to different aspects of reading.This research was supported by PHS grant HD 21887 to Bowman Gray School of Medicine and by PHS Grant NS 19413 to UNC-Greensboro Subcontract to Bowman Gray School of Medicine.     

Comprehension of humor in children with nonverbal learning disabilities,reading disabilities,and without learning disabilities

The normal development of humor in children has been well documented with a predictable course that is tied to social, cognitive, and linguistic development in children. This study explored humor comprehension in children with nonverbal learning disabilities (NVLD). Children with NVLD were compared with children with reading disabilities and a comparison group of children with no learning disabilities to assess their comprehension of humor. The humor test was composed of a joke and cartoon section. No group differences in humor comprehension were found when the NVLD group was defined as having visual–spatial and visual reasoning deficits. However, when the NVLD group was divided into children with and without social perceptual difficulties as defined by a direct measure of social comprehension, significant group differences were found in the levels of humor comprehension. These results support the association of humor comprehension with social perception and lend tentative support to the hypothesis that children with NVLD may not be a homogenous group. Future study directions include further exploration into the nature of the association between humor comprehension and social perception as well as closer examination of the heterogeneity of NVLD.     

The relative roles of IQ and cognitive processes in reading disability

The purpose of the present study was to explore the relative roles of IQ and cognitive processes in reading performance. A sample of 443 Spanish children (264 male, 179 female) ranging in age from 7 to 13 years were classified into four groups according to IQ scores (<80, 80–90, 90–110, >110) and reading disabled (RD) and normally achieving readers (NR) were compared. The findings indicate that IQ scores were not related to the differences between children with RD and NR. We found that reading‐related cognitive deficits do differentiate between RD and NR children. Therefore, IQ scores do not make a significant contribution to our understanding of reading disability.     

The efficacy of `whole word' versus `analytic' reading instruction for children with Down syndrome

An intervention study was conducted toinvestigate whether children with Down syndrome(DS) would benefit from an `analytic' approachto reading instruction, which encompassedexplicit training in phonological awareness.Participants were seven English-speakingchildren with DS aged 8;6 (years;months) to11;1, who demonstrated little or nononword-reading ability prior to intervention.The children received weekly instruction (forsix weeks) in reading aloud 30 regularly speltmonosyllables (e.g., ten, bake) using an`analytic' approach, in which words werelearned by combining onsets with rimes (fourchildren), or a `whole-word' approach (threechildren). Participants' oral reading wasassessed pre- and post-intervention using areading test comprising the 30 trained wordsand 30 untrained (generalisation) words. Mostchildren (six out of seven) read more trainingwords correctly after intervention than before,with significant improvement shown by fourchildren (two trained analytically, and twotrained with whole words). More importantly,reading of generalisation words improvedsignificantly in only three children, all ofwhom had received analytic training. It wasconcluded that children with DS benefit from ananalytic approach to reading instruction, eventhough their auditory-verbal memory (assessedusing digit span) is poor.     

20年来国内学习困难学生研究综述

学习困难问题是近20年来国内外心理学者研究的一个热点问题,如何提高这一类学生的学习能力具有重要意义。该文叙述了我国近年来有关学习困难研究的主要特点和主要研究领域,包括学习困难的界定和类型、学习困难的心理特点以及教育干预等方面的成果,在此基础上提出了未来研究要解决的问题。     

教育史研究的教育学内涵

教育史研究的教育学内涵是一个需要澄清的问题,这将有利于教育史研究自身的进化。超越具体的教育历史事实,用思辨的方式追寻教育历史发展的逻辑,是教育史研究具有教育学内涵的重要途径。这种努力具体体现为通过教育活动史、教育思想史、教育制度史研究,对教育活动、教育思想、教育制度历史发展逻辑的追寻。为此,研究者需要拥有教育学的立场和哲学的方法。     

Use of context in the word recognition process by adults with a significant history of reading difficulties

We examined whether university students who report a significant history of reading difficulties (RD; n = 24) differed from university students with no history of reading difficulties (NRD; n = 31) in how sentence context affects word recognition. Experiment 1 found no differences in how congruent sentence primes or syntactic manipulations of the sentence primes affected the performance of the two groups. However, only the RD group displayed a significant inhibition effect when the target word was preceded by an incongruent sentence prime. Experiment 2 found that the groups differed in how meaning frequency of the target word and context strength of the sentence prime affected word recognition latencies. The results suggest that the RD participants’ performance is context-sensitive and better explained by interactive models of language processing than by modular models.     

A reading-level match study of phonemic processes underlying reading disabilities in a transparent orthography

The current study examined the relationship in Spanish (i.e., a transparent orthography) between different levels of phonological awareness and reading disabilities. In addition, the strategies used by the children when they resolved phoneme segmentation and reversal tasks were analyzed. A sample of 133 subjects were selected and organized in three different groups: (1) A group of 45 reading-disabled children, (2) A comparison group of 44 normal readers matched in age with the reading disabled, and (3) A reading level match group of 44 younger normal readers at the same reading level as the reading disabled. Three phonological awareness tasks were used to measure levels of intrasyllabic and phonemic awareness. The reading disabled group was equivalent to the younger reading level-matched control group in the odd-word-out task. However, there were differences in the phonemic tasks (e.g., phoneme segmentation and reversal) because the reading disabled group performed more poorly than the younger children. Overall, the children matched in age with the reading disabled group were superior in all phonological awareness tasks. There were differences between the groups when the strategies used by the children were analyzed.     

Diagnostic studies of children with specific reading disability as applied in Irvington,New Jersey,public schools

Annals of Dyslexia - Our work over the past eleven years with children with specific reading disability seen in a hospital mental hygiene clinic, in private practice, and in the public schools has...     

Reading disability in boys and girls: No evidence for a differential genetic etiology

In order to test the hypothesis that genetic influences are moreimportant as a cause of reading disability in girls than in boys,composite reading performance data from identical and fraternal twinpairs were analyzed using both concordance and multiple regressionmethods. The sample included 206 identical (99 male, 107 female), 159same-sex fraternal (90 male, 69 female), and 117 opposite-sex fraternaltwin pairs, in which at least one member of each pair had readingdifficulties. Although the difference between the concordance rates forreading disabilities in female identical and same-sex fraternal twinpairs was somewhat greater (65% for identical twins vs.32% for fraternal twins) than the difference in concordance ratesfor boys (68% vs. 39%), loglinear analysis of thesecategorical data revealed that the interaction between sex, zygosity,and concordance was not significant (p > 0.70). Moreover,the heritability of reading disability(h²_g) estimated from regression analysisof the reading performance data in males was nearly identical to that infemales (h²_g = 0.58 and 0.59,respectively; p > 0.90). Thus, results of this studyprovide little or no evidence for the hypothesis of greater geneticinfluence on reading difficulties in girls than in boys.     

一类双险种风险模型的破产概率

在考虑投资因素以及保费收入随机性的基础上研究了一类双险种风险模型,对此模型得到了最终破产概率的一般表达式,Lundberg不等式和破产概率的一个上界.