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.

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.

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.

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.

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.

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.

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.

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.

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.

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.

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.

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.

Language deficits in poor comprehenders: a case for the simple view of reading.

PURPOSE: To examine concurrently and retrospectively the language abilities of children with specific reading comprehension deficits ("poor comprehenders") and compare them to typical readers and children with specific decoding deficits ("poor decoders"). METHOD: In Study 1, the authors identified 57 poor comprehenders, 27 poor decoders, and 98 typical readers on the basis of 8th-grade reading achievement. These subgroups' performances on 8th-grade measures of language comprehension and phonological processing were investigated. In Study 2, the authors examined retrospectively subgroups' performances on measures of language comprehension and phonological processing in kindergarten, 2nd, and 4th grades. Word recognition and reading comprehension in 2nd and 4th grades were also considered. RESULTS: Study 1 showed that poor comprehenders had concurrent deficits in language comprehension but normal abilities in phonological processing. Poor decoders were characterized by the opposite pattern of language abilities. Study 2 results showed that subgroups had language (and word recognition) profiles in the earlier grades that were consistent with those observed in 8th grade. Subgroup differences in reading comprehension were inconsistent across grades but reflective of the changes in the components of reading comprehension over time. CONCLUSIONS: The results support the simple view of reading and the phonological deficit hypothesis. Furthermore, the findings indicate that a classification system that is based on the simple view has advantages over standard systems that focus only on word recognition and/or reading comprehension.

Pro-nominal reference skills of second and fourth grade children with language impairment.

UNLABELLED: Pro-nominal referencing was evaluated in a sample of 569 children comprising four diagnostic subgroups: typical language (TL), specific language impairment (SLI), nonspecific language impairment (NLI), and typical language with low nonverbal IQ (LNIQ). Participants generated oral narratives in second grade and again in fourth grade. The narratives of the females in the TL group included a significantly higher rate of pro-nominal references than the narratives of both the males in the TL group and the females in the NLI group. A higher percentage of complete pro-nominal references was found in the TL group compared to the SLI group. These findings suggest that pro-nominal referencing measures are not sensitive enough to differentiate school-aged children with typical language development from those with language impairment. LEARNING OUTCOMES: The reader will: (1) become familiar with narrative language measures and (2) learn how groups of children with varying language and cognitive profiles perform on measures of referential cohesion.

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.

Are specific language impairment and dyslexia distinct disorders?

PURPOSE: The purpose of this study was to determine whether specific language impairment (SLI) and dyslexia are distinct developmental disorders. METHOD: Study 1 investigated the overlap between SLI identified in kindergarten and dyslexia identified in 2nd, 4th, or 8th grades in a representative sample of 527 children. Study 2 examined phonological processing in a subsample of participants, including 21 children with dyslexia only, 43 children with SLI only, 18 children with SLI and dyslexia, and 165 children with typical language/reading development. Measures of phonological awareness and nonword repetition were considered. RESULTS: Study 1 showed limited but statistically significant overlap between SLI and dyslexia. Study 2 found that children with dyslexia or a combination of dyslexia and SLI performed significantly less well on measures of phonological processing than did children with SLI only and those with typical development. Children with SLI only showed only mild deficits in phonological processing compared with typical children. CONCLUSIONS: These results support the view that SLI and dyslexia are distinct but potentially comorbid developmental language disorders. A deficit in phonological processing is closely associated with dyslexia but not with SLI when it occurs in the absence of dyslexia.

The relationship between phonological awareness and reading: implications for the assessment of phonological awareness.

PURPOSE: Speech-language pathologists (SLPs) use phonological awareness assessments in many ways. This study examines the usefulness of these assessments in kindergarten and 2nd grade. METHOD: Measures of phonological awareness and letter identification were administered in kindergarten, and measures of phonological awareness, phonetic decoding (i.e., nonword reading), and word reading were administered in 2nd and 4th grades to a sample of 570 children participating in a longitudinal study of reading and language impairments. RESULTS: A path analysis indicated that kindergarten measures of phonological awareness and letter identification provided information to the prediction of 2nd-grade reading. In 2nd grade, measures of reading offered information to the prediction of 4th-grade reading. Additionally, a reciprocal relationship was found between phonological awareness and word reading, with kindergarten phonological awareness predicting 2nd-grade word reading and, conversely, 2nd-grade word reading predicting 4th-grade phonological awareness. CLINICAL IMPLICATIONS: Phonological awareness assessment provides information about reading in kindergarten but loses its predictive power at 2nd grade. At that time, phonological awareness and word reading become so highly correlated that phonological awareness does not add information to the prediction of 4th-grade reading.

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.