Bilingualism and Biliteracy in Down Syndrome: Insights From a Case Study.

We present the case study of MB-a bilingual child with Down syndrome (DS) who speaks Russian (first language [L1]) and English (second language [L2]) and has learned to read in two different alphabets with different symbol systems. We demonstrate that, in terms of oral language, MB is as proficient in Russian as English, with a mild advantage for reading in English, her language of formal instruction. MB's L1 abilities were compared with those of 11 Russian-speaking typically developing monolinguals and her L2 abilities to those of 15 English-speaking typically developing monolinguals and six monolingual English-speaking children with DS; each group achieving the same level of word reading ability as MB. We conclude that learning two languages in the presence of a learning difficulty need have no detrimental effect on either a child's language or literacy development.

Evidence for semantic involvement in regular and exception word reading in emergent readers of English.

We investigated the relationship between semantic knowledge and word reading. A sample of 27 6-year-old children read words both in isolation and in context. Lexical knowledge was assessed using general and item-specific tasks. General semantic knowledge was measured using standardized tasks in which children defined words and made judgments about the relationships between words. Item-specific knowledge of to-be-read words was assessed using auditory lexical decision (lexical phonology) and definitions (semantic) tasks. Regressions and mixed-effects models indicated a close relationship between semantic knowledge (but not lexical phonology) and both regular and exception word reading. Thus, during the early stages of learning to read, semantic knowledge may support word reading irrespective of regularity. Contextual support particularly benefitted reading of exception words. We found evidence that lexical-semantic knowledge and context make separable contributions to word reading.

Language profiles and literacy outcomes of children with resolving, emerging, or persisting language impairments.

BACKGROUND: Children with language impairment (LI) show heterogeneity in development. We tracked children from pre-school to middle childhood to characterize three developmental trajectories: resolving, persisting and emerging LI. METHODS: We analyzed data from children identified as having preschool LI, or being at family risk of dyslexia, together with typically developing controls at three time points: t1 (age 3;09), t3 (5;08) and t5 (8;01). Language measures are reported at t1, t3 and t5, and literacy abilities at t3 and t5. A research diagnosis of LI (irrespective of recruitment group) was validated at t1 by a composite language score derived from measures of receptive and expressive grammar and vocabulary; a score falling 1SD below the mean of the typical language group on comparable measures at t3 and t5 was used to determine whether a child had LI at later time points and then to classify LIs as resolving, persisting or emerging. RESULTS: Persisting preschool LIs were more severe and pervasive than resolving LIs. Language and literacy outcomes were relatively poor for those with persisting LI, and relatively good for those with resolving LI. A significant proportion of children with average language abilities in preschool had LIs that emerged in middle childhood - a high proportion of these children were at family risk of dyslexia. There were more boys in the persisting and resolving LI groups. Children with early LIs which resolved by the start of formal literacy instruction tended to have good literacy outcomes; children with late-emerging difficulties that persisted developed reading difficulties. CONCLUSIONS: Children with late-emerging LI are relatively common and are hard to detect in the preschool years. Our findings show that children whose LIs persist to the point of formal literacy instruction frequently experience reading difficulties.

Early prediction of language and literacy problems: is 18 months too early?

There is a lack of stability in language difficulties across early childhood: most late talkers (LTs) resolve their difficulties by pre-school; and a significant number of children who were not LTs subsequently manifest language difficulties. Greater reliability in predicting individual outcomes is needed, which might be achieved by waiting until later in development when language is more stable. At 18 months, productive vocabulary scores on the Oxford Communicative Developmental Inventory were used to classify children as LTs or average talkers (ATs). Thirty matched-pairs of LTs and ATs were followed up at school-age (average age 7 years), when language and literacy outcomes were assessed. For 18 children, intermediate testing at age 4 had classified them as showing typical development (TD) or specific language impairment (SLI). After correcting for multiple comparisons, there were no significant differences between the LTs and ATs on any outcome measure, and the LTs were performing in the average range. However, there were large-sized effects on all outcomes when comparing the TD and SLI groups. LT status on its own is not determinative of language and literacy difficulties. It would therefore not be appropriate to use expressive vocabulary measures alone to screen for language difficulties at 18 months. However, children with language impairment at age 4 are at risk of enduring difficulties.

Do infant vocabulary skills predict school-age language and literacy outcomes?

BACKGROUND: Strong associations between infant vocabulary and school-age language and literacy skills would have important practical and theoretical implications: Preschool assessment of vocabulary skills could be used to identify children at risk of reading and language difficulties, and vocabulary could be viewed as a cognitive foundation for reading. However, evidence to date suggests predictive ability from infant vocabulary to later language and literacy is low. This study provides an investigation into, and interpretation of, the magnitude of such infant to school-age relationships. METHODS: Three hundred British infants whose vocabularies were assessed by parent report in the 2nd year of life (between 16 and 24 months) were followed up on average 5 years later (ages ranged from 4 to 9 years), when their vocabulary, phonological and reading skills were measured. RESULTS: Structural equation modelling of age-regressed scores was used to assess the strength of longitudinal relationships. Infant vocabulary (a latent factor of receptive and expressive vocabulary) was a statistically significant predictor of later vocabulary, phonological awareness, reading accuracy and reading comprehension (accounting for between 4% and 18% of variance). Family risk for language or literacy difficulties explained additional variance in reading (approximately 10%) but not language outcomes. CONCLUSIONS: Significant longitudinal relationships between preliteracy vocabulary knowledge and subsequent reading support the theory that vocabulary is a cognitive foundation of both reading accuracy and reading comprehension. Importantly however, the stability of vocabulary skills from infancy to later childhood is too low to be sufficiently predictive of language outcomes at an individual level - a finding that fits well with the observation that the majority of 'late talkers' resolve their early language difficulties. For reading outcomes, prediction of future difficulties is likely to be improved when considering family history of language/literacy difficulties alongside infant vocabulary levels.

Reading and language intervention for children at risk of dyslexia: a randomised controlled trial.

BACKGROUND: Intervention studies for children at risk of dyslexia have typically been delivered preschool, and show short-term effects on letter knowledge and phoneme awareness, with little transfer to literacy. METHODS: This randomised controlled trial evaluated the effectiveness of a reading and language intervention for 6-year-old children identified by research criteria as being at risk of dyslexia (n = 56), and their school-identified peers (n = 89). An Experimental group received two 9-week blocks of daily intervention delivered by trained teaching assistants; the Control group received 9 weeks of typical classroom instruction, followed by 9 weeks of intervention. RESULTS: Following mixed effects regression models and path analyses, small-to-moderate effects were shown on letter knowledge, phoneme awareness and taught vocabulary. However, these were fragile and short lived, and there was no reliable effect on the primary outcome of word-level reading. CONCLUSIONS: This new intervention was theoretically motivated and based on previous successful interventions, yet failed to show reliable effects on language and literacy measures following a rigorous evaluation. We suggest that the intervention may have been too short to yield improvements in oral language; and that literacy instruction in and beyond the classroom may have weakened training effects. We argue that reporting of null results makes an important contribution in terms of raising standards both of trial reporting and educational practice.

The causal role of phoneme awareness and letter-sound knowledge in learning to read: combining intervention studies with mediation analyses.

There is good evidence that phoneme awareness and letter-sound knowledge are reliable longitudinal predictors of learning to read, though whether they have a causal effect remains uncertain. In this article, we present the results of a mediation analysis using data from a previous large-scale intervention study. We found that a phonology and reading intervention that taught letter-sound knowledge and phoneme awareness produced significant improvements in these two skills and in later word-level reading and spelling skills. Improvements in letter-sound knowledge and phoneme awareness at the end of the intervention fully mediated the improvements seen in children's word-level literacy skills 5 months after the intervention finished. Our findings support the conclusion that letter-sound knowledge and phoneme awareness are two causal influences on the development of children's early literacy skills.

Efficacy of a reading and language intervention for children with Down syndrome: a randomized controlled trial.

BACKGROUND: This study evaluates the effects of a language and literacy intervention for children with Down syndrome. METHODS: Teaching assistants (TAs) were trained to deliver a reading and language intervention to children in individual daily 40-min sessions. We used a waiting list control design, in which half the sample received the intervention immediately, whereas the remaining children received the treatment after a 20-week delay. Fifty-seven children with Down syndrome in mainstream primary schools in two U.K. locations (Yorkshire and Hampshire) were randomly allocated to intervention (40 weeks of intervention) and waiting control (20 weeks of intervention) groups. Assessments were conducted at three time points: pre-intervention, after 20 weeks of intervention, and after 40 weeks of intervention. RESULTS: After 20 weeks of intervention, the intervention group showed significantly greater progress than the waiting control group on measures of single word reading, letter-sound knowledge, phoneme blending and taught expressive vocabulary. Effects did not transfer to other skills (nonword reading, spelling, standardised expressive and receptive vocabulary, expressive information and grammar). After 40 weeks of intervention, the intervention group remained numerically ahead of the control group on most key outcome measures; but these differences were not significant. Children who were younger, attended more intervention sessions, and had better initial receptive language skills made greater progress during the course of the intervention. CONCLUSIONS: A TA-delivered intervention produced improvements in the reading and language skills of children with Down syndrome. Gains were largest in skills directly taught with little evidence of generalization to skills not directly taught in the intervention.

Practitioner Review: Reading disorders: what are the effective interventions and how should they be implemented and evaluated?

BACKGROUND: Two developmental reading disorders, dyslexia and reading comprehension impairment, are identified by different behavioural characteristics and traced back to different underlying cognitive impairments. Thus, reading interventions designed to address each of these reading disorders differ in content. METHOD: This review summarises the nature of dyslexia and reading comprehension impairment, and current understanding of best practice in associated reading interventions. CONCLUSION: There is strong evidence for the effectiveness of phonological-based reading interventions in supporting children with dyslexic difficulties, and a growing understanding of how to meet the needs of children with reading comprehension impairment, with vocabulary instruction offering a promising approach. Although the content of interventions must be tailored to an individual's reader profile, general principles regarding the implementation and evaluation of intervention programmes can be extracted.

Improving early language and literacy skills: differential effects of an oral language versus a phonology with reading intervention.

BACKGROUND: This study compares the efficacy of two school-based intervention programmes (Phonology with Reading (P + R) and Oral Language (OL)) for children with poor oral language at school entry. METHODS: Following screening of 960 children, 152 children (mean age 4;09) were selected from 19 schools on the basis of poor vocabulary and verbal reasoning skills and randomly allocated to either the P + R programme or the OL programme. Both groups of children received 20 weeks of daily intervention alternating between small group and individual sessions, delivered by trained teaching assistants. Children in the P + R group received training in letter-sound knowledge, phonological awareness and book level reading skills. Children in the OL group received instruction in vocabulary, comprehension, inference generation and narrative skills. The children's progress was monitored at four time points: pre-, mid- and post-intervention, and after a 5-month delay, using measures of literacy, language and phonological awareness. RESULTS: The data are clustered (children within schools) and robust confidence intervals are reported. At the end of the 20-week intervention programme, children in the P + R group showed an advantage over the OL group on literacy and phonological measures, while children in the OL group showed an advantage over the P + R group on measures of vocabulary and grammatical skills. These gains were maintained over a 5-month period. CONCLUSIONS: Intervention programmes designed to develop oral language skills can be delivered successfully by trained teaching assistants to children at school entry. Training using P + R fostered decoding ability whereas the OL programme improved vocabulary and grammatical skills that are foundations for reading comprehension. However, at the end of the intervention, more than 50% of at-risk children remain in need of literacy support.