Revisiting the definition of dyslexia.

The International Dyslexia Association definition of dyslexia was updated 20 years ago and has been referenced frequently in research and practice. In this paper, researchers from the Florida Center for Reading Research consider the components of the definition and make recommendations for revisions. These include recognizing the persistence of word-reading, decoding, and spelling difficulties, acknowledging the multifactorial causal basis of dyslexia, clarifying exclusionary factors, and denoting comorbidity with other developmental disorders. It is also suggested that the academic and psychosocial consequences of dyslexia be highlighted to reinforce a preventive service delivery model. Lastly, the inclusion of dyslexia within a specific learning disability category is supported.

A Cumulative Risk and Resilience Model of Dyslexia.

Considerable attention and legislation are currently focused on developmental dyslexia. A major challenge to these efforts is how to define and operationalize dyslexia. In this article, we argue that rather than defining dyslexia on the basis of an underlying condition, dyslexia is best viewed as a label for an unexpected reading disability. This view fits well with a preventive approach in which risk for reading disability is identified and addressed prior to children experiencing reading failure. A risk-resilience model is introduced that proposes that dyslexia is due to the cumulative effects of risk and resilience factors. Evidence for the multifactorial causal basis of dyslexia is reviewed and potential factors that may offset this risk are considered. The implications of a cumulative risk and resilience model for early identification and intervention is discussed.

Commentary: The critical role of oral language deficits in reading disorders: reflections on Snowling and Hulme (2021).

Learning to read is a primary goal of early education, and considerable instructional time is focused on it. Most children respond well to this instruction and soon become accurate and fluent readers. But a small percentage of children find learning to read a significant challenge and often struggle educationally and psychologically as a result. In an earlier review, Snowling and Hulme (2012) argued that weaknesses in oral language development play a causal role in reading disorders such as dyslexia and reading comprehension impairment. They further proposed that these impairments should be recognized as distinct disorders within the DSM-5 classification system. In the current review, Snowling and Hulme (this issue) consider how risk factors at the biological, cognitive, and environmental levels combine to cause reading disorders. Again, they focus particular attention on oral language development and its critical role in reading success/failure.

Predicting Dyslexia in Children With Developmental Language Disorder.

Purpose In this study, we examine how well kindergarten letter identification and phonological awareness predict 2nd grade word reading and dyslexia in children with developmental language disorder (DLD) and their age- and grade-matched peers with typical language (TL). Method We employ (a) logistic regression to determine how letter identification and phonological awareness predict dyslexia, that is, dichotomous categorization of good or poor word reading, in children with DLD and TL and (b) quantile regression to determine how letter identification and phonological awareness are associated with word reading abilities on a continuum in these groups of children. Results Logistic regression revealed that letter identification was the only significant, unique kindergarten predictor of dyslexia in 2nd grade children with DLD, when compared to phonological awareness. In children with TL, both kindergarten letter identification and phonological awareness significantly predicted dyslexia in 2nd grade. Quantile regression revealed that kindergarten letter identification was a stronger predictor of 2nd grade word reading for average and lower achieving word readers with DLD and their peers with TL compared to higher performing readers. Phonological awareness was weakly associated with word reading across the full continuum of word reading abilities in children with DLD. Conclusion Letter identification is a more accurate predictor of poor word reading and dyslexia than phonological awareness in kindergarten children with DLD, which has important implications for recent U.S. legislation around early identification of dyslexia in all children.

How the Science of Reading Informs 21st-Century Education.

The science of reading should be informed by an evolving evidence base built upon the scientific method. Decades of basic research and randomized controlled trials of interventions and instructional routines have formed a substantial evidence base to guide best practices in reading instruction, reading intervention, and the early identification of at-risk readers. The recent resurfacing of questions about what constitutes the science of reading is leading to misinformation in the public space that may be viewed by educational stakeholders as merely differences of opinion among scientists. Our goals in this paper are to revisit the science of reading through an epistemological lens to clarify what constitutes evidence in the science of reading and to offer a critical evaluation of the evidence provided by the science of reading. To this end, we summarize those things that we believe have compelling evidence, promising evidence, or a lack of compelling evidence. We conclude with a discussion of areas of focus that we believe will advance the science of reading to meet the needs of all children in the 21st century.

Conditional Longitudinal Relations of Elementary Literacy Skills to High School Reading Comprehension.

The present study explores the longitudinal development between Grade 3 word level reading skills and higher level semantic skills to Grade 10 reading comprehension for 3,157 students. In particular, this work focused on how the developmental relations varied for subsamples of students who are English learners (EL; N = 308), students identified as specific learning disability (SLD; N = 133), and general education (Gen Ed; N = 2,716) students who have no formal classification or diagnoses. Multiple group structural equation modeling showed that the relation between Grade 3 vocabulary and Grade 10 reading comprehension did not vary across three student subgroups when accounting for Grade 3 fluency and that when controlling for students' vocabulary, the unique effect of oral reading fluency ranged from a standardized effect of γ = .22 to γ = .39 across the three subgroups. Quantile regression using estimated factor scores revealed heterogeneous relations of component skills to reading comprehension across each subgroup.

Prologue: Reading Comprehension Is Not a Single Ability.

Purpose: In this initial article of the clinical forum on reading comprehension, we argue that reading comprehension is not a single ability that can be assessed by one or more general reading measures or taught by a small set of strategies or approaches. Method: We present evidence for a multidimensional view of reading comprehension that demonstrates how it varies as a function of reader ability, text, and task. The implications of this view for instruction of reading comprehension are considered. Conclusion: Reading comprehension is best conceptualized with a multidimensional model. The multidimensionality of reading comprehension means that instruction will be more effective when tailored to student performance with specific texts and tasks.

Epilogue: Reading Comprehension Is Not a Single Ability-Implications for Assessment and Instruction.

Purpose: In this epilogue, we review the 4 response articles and highlight the implications of a multidimensional view of reading for the assessment and instruction of reading comprehension. Method: We reiterate the problems with standardized tests of reading comprehension and discuss the advantages and disadvantages of recently developed authentic tests of reading comprehension. In the "Instruction" section, we review the benefits and limitations of strategy instruction and highlight suggestions from the response articles to improve content and language knowledge. Conclusions: We argue that the only compelling reason to administer a standardized test of reading comprehension is when these tests are necessary to qualify students for special education services. Instruction should be focused on content knowledge, language knowledge, and specific task and learning requirements. This instruction may entail the use of comprehension strategies, particularly those that are specific to the task and focus on integrating new knowledge with prior knowledge.

Early Identification of Reading Comprehension Difficulties.

Most research on early identification of reading disabilities has focused on word reading problems and little attention has been given to reading comprehension difficulties. In this study, we investigated whether measures of language ability and/or response to language intervention in kindergarten uniquely predicted reading comprehension difficulties in third grade. A total of 366 children were administered a battery of screening measures at the beginning of kindergarten and progress monitoring probes across the school year. A subset of children also received a 26-week Tier 2 language intervention. Participants' achievement in word reading was assessed at the end of second grade, and their performance in reading comprehension was measured as the end of third grade. Results showed that measures of language ability in kindergarten significantly added to the prediction of reading comprehension difficulties over and above kindergarten word reading predictors and direct measures of word reading in second grade. Response to language intervention also proved to be a unique predictor of reading comprehension outcomes. Findings are discussed in terms of their relevance for the early identification of reading disabilities.

Morphosyntax in Poor Comprehenders.

Children described as poor comprehenders (PCs) have reading comprehension difficulties in spite of adequate word reading abilities. PCs are known to display weakness with semantics and higher-level aspects of oral language, but less is known about their grammatical skills, especially with regard to morphosyntax. The purpose of this study was to examine morphosyntax in fourth grade PCs and typically developing readers (TDs), using three experimental tasks involving finiteness marking. Participants also completed standardized, norm-referenced assessments of phonological memory, vocabulary, and broader language skills. PCs displayed weakness relative to TDs on all three morphosyntax tasks and on every other assessment of oral language except phonological memory, as indexed by nonword repetition. These findings help to clarify the linguistic profile of PCs, suggesting that their language weaknesses include grammatical weaknesses that cannot be fully explained by semantic factors. Because finiteness markers are usually mastered prior to formal schooling in typical development, we call for future studies to examine whether assessments of morphosyntax could be used for the early identification of children at risk for future reading comprehension difficulty.

Early identification of reading disabilities within an RTI framework.

Early and accurate identification of children at risk for reading disabilities (RD) is critical for the prevention of RD within a response to intervention framework. In this study, we investigated the use of universal screening and progress monitoring for the early identification of RD in kindergarten children. A total of 366 children were administered a battery of screening measures at the beginning of kindergarten and progress-monitoring probes across the school year. A subset of children who showed initial risk for RD also received a 26-week Tier 2 intervention. Participants' achievement in word reading accuracy and/or fluency was assessed at the end of first grade. Results indicated that a screening battery containing measures of letter naming fluency, phonological awareness, rapid naming, or nonword repetition accurately identified good and poor readers at the end of first grade. Findings also showed that children's response to supplemental and/or classroom instruction measured in terms of growth in letter naming fluency added significantly to the prediction of reading outcomes.

Is weak oral language associated with poor spelling in school-age children with specific language impairment, dyslexia or both?

The purpose of this study was to test the hypothesis that word reading accuracy, not oral language, is associated with spelling performance in school-age children. We compared fourth grade spelling accuracy in children with specific language impairment (SLI), dyslexia or both (SLI/dyslexia) to their typically developing grade-matched peers. Results of the study revealed that children with SLI performed similarly to their typically developing peers on a single-word spelling task. Alternatively, those with dyslexia and SLI/dyslexia evidenced poor spelling accuracy. Errors made by both those with dyslexia and SLI/dyslexia were characterized by numerous phonologic, orthographic and semantic errors. Cumulative results support the hypothesis that word reading accuracy, not oral language, is associated with spelling performance in typically developing school-age children and their peers with SLI and dyslexia. Findings are provided as further support for the notion that SLI and dyslexia are distinct, yet co-morbid, developmental disorders.

Prevalence and Nature of Late-Emerging Poor Readers.

Some children demonstrate adequate or better reading achievement in early school grades, but fall significantly behind their peers in later grades. These children are often referred to as late-emerging poor readers. In this study, we investigated the prevalence and heterogeneity of these poor readers. We also examined the early language and nonverbal cognitive abilities of late-emerging poor readers. Participants were 493 children who were a subsample from an epidemiological study of language impairments in school-age children. In kindergarten, children were administered a battery of language, early literacy, and nonverbal cognitive measures. Word reading and reading comprehension achievement was assessed in second, fourth, eighth, and tenth grades. Latent transition analysis was used to model changes in reading classification (good vs. poor reader) across grades. Population estimates revealed that 13.4% percent of children could be classified as late-emerging poor readers. These children could be divided into those with problems in comprehension alone (52%), word reading alone (36%), or both (12%). Further results indicated that late-emerging poor readers often had a history of language and/or nonverbal cognitive impairments in kindergarten. Subtypes of poor readers also differed significantly in their profiles of language, early literacy, and nonverbal cognitive abilities in kindergarten. Results are discussed in terms of causal factors and implications for early identification.

The use of a dynamic screening of phonological awareness to predict risk for reading disabilities in kindergarten children.

This study examined the usefulness and predictive validity of a dynamic screening of phonological awareness in two samples of kindergarten children. In one sample (n = 90), the predictive validity of the dynamic assessment was compared to a static version of the same screening measure. In the second sample (n = 96), the dynamic screening measure was compared to a commonly used screening tool, Dynamic Indicators of Basic Early Literacy Skills Initial Sound Fluency. Results showed that the dynamic screening measure uniquely predicted end-of-year reading achievement and outcomes in both samples. These results provide preliminary support for the usefulness of a dynamic screening measure of phonological awareness for kindergarten students.

The influence of neighborhood density and word frequency on phoneme awareness in 2nd and 4th grades.

PURPOSE: The purpose of this study was to test the hypothesis that two lexical characteristics - neighborhood density and word frequency - interact to influence performance on phoneme awareness tasks. METHODS: Phoneme awareness was examined in a large, longitudinal dataset of 2nd and 4th grade children. Using linear logistic test model, the relation between words' neighborhood density, word frequency, and phoneme awareness performance was examined across grades while co-varying type and place of deletion. RESULTS: A predicted interaction was revealed: words from dense neighborhoods or those with high frequency were more likely to yield correct phoneme awareness responses across grades. CONCLUSIONS: Findings support an expansion of the lexical restructuring model to include interactions between neighborhood density and word frequency to account for phoneme awareness. LEARNING OUTCOMES: The reader will be able to (1) describe the lexical restructuring model; (2) define neighborhood density; (3) define word frequency; (4) identify how these variables interact to impact phoneme awareness performance; (5) identify ways in which future clinical practice may be impacted by the study's findings.

Kindergarten predictors of second versus eighth grade reading comprehension impairments.

Multiple studies have shown that kindergarten measures of phonological awareness and alphabet knowledge are good predictors of reading achievement in the primary grades. However, less attention has been given to the early predictors of later reading achievement. This study used a modified best-subsets variable-selection technique to examine kindergarten predictors of early versus later reading comprehension impairments. Participants included 433 children involved in a longitudinal study of language and reading development. The kindergarten test battery assessed various language skills in addition to phonological awareness, alphabet knowledge, naming speed, and nonverbal cognitive ability. Reading comprehension was assessed in second and eighth grades. Results indicated that different combinations of variables were required to optimally predict second versus eighth grade reading impairments. Although some variables effectively predicted reading impairments in both grades, their relative contributions shifted over time. These results are discussed in light of the changing nature of reading comprehension over time. Further research will help to improve the early identification of later reading disabilities.

The narrow view of reading promotes a broad view of comprehension.

PURPOSE: This article is a response to A. G. Kamhi's proposal of the narrow view of reading. METHOD: A descriptive approach is used to review research concerning the cognitive basis of reading comprehension. Educational implications for instruction and assessment are considered. The role of the speech-language pathologist (SLP) in intervention related to reading comprehension is also addressed. CONCLUSION: Although the narrow view of reading seems restrictive, it actually leads to a broad view of comprehension. The latter view, which is consistent with current research, proposes that comprehension is an active process in which readers use background knowledge and a range of cognitive processes to construct a coherent representation of text. This view challenges some current approaches to assessment and instruction of reading comprehension. It does not, however, diminish the role that SLPs can play in intervention related to reading comprehension.

Floor effects associated with universal screening and their impact on the early identification of reading disabilities.

Response to intervention (RTI) holds great promise for the early identification and prevention of reading disabilities. The success of RTI rests in part on the accuracy of universal screening tools used within this framework. Despite advancements, screening instruments designed to identify children at risk for reading disabilities continue to have limited predictive validity. In this study, the authors examined a common screening instrument for the presence of floor effects and investigated the impact that these effects have on the predictive validity of the instrument. Longitudinal data (kindergarten to third grade) from a large cohort of children were used. These data included children's performance on five measures from the Dynamic Indicators of Basic Early Literacy Skills (DIBELS) and two reading achievement outcome measures. The results showed that DIBELS measures were characterized by floor effects in their initial administrations and that these effects reduced the predictive validity of the measures. The implications of these findings for early identification are discussed.

Reading achievement growth in children with language impairments.

PURPOSE: This study examined the reading achievement growth of children with language impairments (LI) across the school grades. The authors sought to determine whether children with LI demonstrate a delayed, deficit, or cumulative pattern of reading achievement growth when compared with children with typical language (TL). METHOD: A group of 225 children with LI and a group of 379 children with TL were identified in kindergarten and were administered multiple measures of word recognition and reading comprehension in 2nd, 4th, 8th, and 10th grades. RESULTS: Confirmatory factor analyses indicated that the constructs of word recognition and reading comprehension were invariant across grades and groups of children with LI and TL. Further analyses indicated that a multiple group latent growth curve analysis was appropriate. This analysis showed that children with LI differed significantly from children with TL in initial level (2nd grade) of word recognition and reading comprehension, but they did not differ significantly in the shape of their growth trajectories. CONCLUSION: These results are consistent with a deficit model of reading growth in children with LI. Findings are discussed in terms of implications for early identification.

Development of oral reading fluency in children with speech or language impairments: a growth curve analysis.

This longitudinal study used piece-wise growth curve analyses to examine growth patterns in oral reading fluency for 1,991 students with speech impairments (SI) or language impairments (LI) from first through third grade. The main finding of this study was that a diagnosis of SI or LI can have a detrimental and persistent effect on early reading skills. Results indicated differences between subgroups in growth trajectories that were evident in first grade. A large proportion of students with SI or LI did not meet grade-level reading fluency benchmarks. Overall students with SI showed better performance than students with LI. Reading fluency performance was negatively related to the persistence of the SI or LI; the lowest performing students were those originally identified with SI or LI whose diagnosis changed to a learning disability. The results underscore the need to identify, monitor, and address reading fluency difficulties early among students with SI or LI.