Development and Prediction of Context-Dependent Vowel Pronunciation in Elementary Readers

The English Sublexical Toolkit: Methods for indexing sound-spelling consistency

This work introduces the English Sublexical Toolkit, a suite of tools that utilizes an experience-dependent learning framework of sublexical knowledge to extract regularities from the English lexicon. The Toolkit quantifies the empirical regularity of sublexical units in both the reading and spelling directions (i.e., grapheme-to-phoneme and phoneme-to-grapheme) and at multiple grain sizes (i.e., phoneme/grapheme and onset/rime unit size). It can extract multiple experience-dependent regularity indices for words or pseudowords, including both frequency indices (e.g., grapheme frequency) and conditional probability indices (e.g., grapheme-to-phoneme probability). These tools provide (1) superior estimates of the regularities that better reflect the complexity of the sublexical system relative to previously published indices and (2) completely novel indices of sublexical units such as phonographeme frequency (i.e., combined units of individual phonemes and graphemes that are independent of processing direction). We demonstrate that measures from the toolkit explain significant amounts of variance in empirical data (naming of real words and lexical decision), and either outperform or are comparable to the best available consistency measures. The flexibility of the toolkit is further demonstrated by its ability to readily index the probability of different pseudowords pronunciations, and we report that the measures account for the majority of variance in these empirically observed probabilities. Overall, this work provides a framework and resources that can be flexibly used to identify optimal corpus-based consistency measures that help explain reading/spelling behaviors for real and pseudowords.

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.

Modeling Item-Level Spelling Variance in Adults: Providing Further Insights into Lexical Quality

Purpose

The lexical quality (LQ) hypothesis predicts that a skilled reader's lexicon will be inhabited by a range of low- to high-quality items, and the probability of representing a word with high quality varies as a function of person-level, word-level, and item-specific variables. These predictions were tested with spelling accuracy as a gauge of LQ.

Method

Item-response based crossed random effects models explored simultaneous contributions of person-level (e.g., participant's decoding skill), word-level (e.g., word's transparency rating), item-specific (e.g., participant's familiarity with specific word), and person-by-word interaction predictors (e.g., decoding by transparency rating interaction) to the spelling of 25 commonly misspelled irregular English words in 61 undergraduate university students (M = 19.4 years, 70.49% female, 39.34% Hispanic, 81.97% White).

Results

Substantial variance among individuals in item-level spelling accuracy was accounted for by person-level decoding skill; item-specific familiarity, proportion of schwas correctly represented, and correctly identifying the word from its mispronunciation; and an interaction of transparency rating by general decoding skill.

Conclusions

Consistent with the LQ hypothesis, results suggest that one's ability to form a high-quality lexical representation of a given word depends on a complex combination of person-level abilities, word-level characteristics, item-specific experiences, and an interaction between person- and word-level influences.

Set for Variability as a Critical Predictor of Word Reading: Potential Implications for Early Identification and Treatment of Dyslexia

Quasiregular orthographies such as English contain substantial ambiguities between orthography and phonology that force developing readers to acquire flexibility during decoding of unfamiliar words, a skill referred to as a "set for variability" (SfV). The ease with which a child can disambiguate the mismatch between the decoded form of a word and its actual lexical phonological form has been operationalized using the SfV mispronunciation task (e.g., the word wasp is pronounced to rhyme with clasp [i.e., /wæsp/] and the child must recognize the actual pronunciation of the word to be /wɒsp/). SfV has been shown to be a significant predictor of word reading variance. However, little is known about the relative strength of SfV as a predictor of word reading compared to other well-established predictors or the strength of this relationship in children with dyslexia. To address these questions, we administered the SfV task to a sample of grade 2-5 children (N=489) along with other reading related measures. SfV accounted for 15% unique variance in word reading above and beyond other predictors, whereas phonological awareness (PA) accounted for only 1%. Dominance analysis indicated SfV is the most powerful predictor, demonstrating complete statistical dominance over other variables including PA. Quantile regression revealed SfV is a stronger predictor at lower levels of reading skill, indicating it may be an important predictor in students with dyslexia. Results suggest that SfV is a powerful and potentially highly sensitive predictor of early reading difficulties and, therefore, may be important for early identification and treatment of dyslexia.

Number and Syllabification of Following Consonants Influence Use of Long Versus Short Vowels in English Disyllables

Spelling-to-sound translation in English is particularly complex for vowels. For example, the pronunciations of ‹a› include the long vowel of ‹paper› and ‹sacred› and the short vowel of ‹cactus› and ‹happy›. We examined the factors that are associated with use of long versus short vowels by conducting analyses of English disyllabic words with single medial consonants and consonant sequences and three behavioral studies in which a total of 119 university students pronounced nonwords with these structures. The vocabulary analyses show that both the number of medial consonants and their syllabification influence vowel length. Participants were influenced by these aspects of context, some of which are not explicitly taught as a part of reading instruction. Although these results point to implicit statistical learning, participants produced fewer long vowels before single medial consonants than anticipated based on our vocabulary statistics for spelling-to-sound correspondences in disyllabic words. Participants also produced more long vowels before two identical consonant letters than anticipated given these statistics. We consider the reasons for these outcomes, and we also use the behavioral data to test two models of spelling-to-sound translation.

Unpacking the Unique Relationship Between Set for Variability and Word Reading Development: Examining Word- and Child-Level Predictors of Performance

Set for variability (SfV) is an oral language task which requires an individual to disambiguate the mismatch between the decoded form of an irregular word and its actual lexical pronunciation. For example, in the task, the word wasp is pronounced to rhyme with clasp (i.e., /wæsp/) and the individual must recognize the actual pronunciation of the word to be /wɒsp/. SfV has been shown to be a significant predictor of both item-specific and general word reading variance above and beyond that associated with phonemic awareness skill, letter-sound knowledge, and vocabulary skill. However, very little is known about the child characteristics and word features that affect SfV item performance. In this study we explored whether word features and child characteristics that involve phonology only are adequate to explain item-level variance in SfV performance or whether including predictors that involve the connection between phonology and orthography explain additional variance. To accomplish this we administered the SfV task (N=75 items) to a sample of grade 2-5 children (N=489) along with a battery of reading, reading related, and language measures. Results suggest that variance in SfV performance is uniquely accounted for by measures tapping phonological skill along with those capturing knowledge of phonology to orthography associations, but more so in children with better decoding skill. Additionally, word reading skill was found to moderate the influence of other predictors suggesting that how the task is approached may be impacted by word reading and decoding ability.

Modeling Complex Word Reading: Examining Influences at the Level of the Word and Child on Mono- and Polymorphemic Word Reading

Purpose

The probability of a child reading a word correctly is influenced by both child skills and properties of the word. The purpose of this study was to investigate child-level skills (set for variability and vocabulary), word-level properties (concreteness), word structure (mono- vs. polymorphemic), and interactions between these properties and word structure within a comprehensive item-level model of complex word reading. This study is unique in that it purposely sampled both mono- and polymorphemic polysyllabic words.

Method

A sample of African American (n = 69) and Hispanic (n =6) students in grades 2-5 (n =75) read a set of mono- and polymorphemic polysyllabic words (J=54). Item-level responses were modeled using cross-classified generalized random-effects models allowing variance to be partitioned between child and word while controlling for other important child factors and word features.

Results

Set for variability and the interaction between concreteness and word structure (i.e., mono- vs. polymorphemic) were significant predictors. Higher probabilities of reading poly- over monomorphemic words were identified at lower levels of concreteness with the opposite at higher levels of concreteness.

Conclusions

Results indicate important predictors at both the child- and word-level and support the importance of morphological structure for reading abstract polysyllabic words.

When two vowels go walking: An ERP study of the vowel team rule

In an event-related potential (ERP) study of the vowel team rule in American English ("when two vowels go walking, the first does the talking"), we used a visual lexical decision task to determine whether words that do (e.g., braid) and do not (e.g., cloud) follow the rule elicit different processing, and to determine if this extends to nonwords (e.g., braip, cloup). In 32 young adults, N1 amplitude distinguished between rule-following and rule-breaking items: N1 amplitude was more negative to rule-breaking words and nonwords. In contrast, there were no significant effects of vowel team rule adherence on N400 amplitude. Behaviorally, participants responded more quickly and accurately to rule-following words, a pattern not observed for nonwords. These findings demonstrate that adherence to the vowel team rule can be indexed by both neural and behavioral measures in fluently reading young adults.

Are people consistent when reading nonwords aloud on different occasions?

Tests of nonword reading have been instrumental in adjudicating between theories of reading and in assessing individuals' reading skill in educational and clinical practice. It is generally assumed that the way in which readers pronounce nonwords reflects their long-term knowledge of spelling-sound correspondences that exist in the writing system. The present study found considerable variability in how the same adults read the same 50 nonwords across five sessions. This variability was not all random: Nonwords that consisted of graphemes that had multiple possible pronunciations in English elicited more intraparticipant variation. Furthermore, over time, shifts in participants' responses occurred such that some pronunciations became used more frequently, while others were pruned. We discuss possible mechanisms by which session-to-session variability arises and implications that our findings have for interpreting snapshot-based studies of nonword reading. We argue that it is essential to understand mechanisms underpinning this session-to-session variability in order to interpret differences across individuals in how they read nonwords aloud on a single occasion.

Initial validation of a measure of decoding difficulty as a unique predictor of miscues and passage reading fluency

Quantifying the decoding difficulty (i.e., 'decodability') of text is important for accurately matching young readers to appropriate text and scaffolding reading development. Since no easily accessible, quantitative, word-level metric of decodability exists, we developed a decoding measure (DM) that can be calculated via a web-based scoring application that takes into account sub-lexical components (e.g. orthographic complexity), thus measuring decodability at the grapheme-phoneme level, which can be used to judge decodability of individual words or passages. Here we report three experiments using the DM: two predicting children's word-level errors and one predicting passage reading fluency. Generalized linear mixed effect models showed that metrics from the DM explained unique variance in children's oral reading miscues after controlling for word frequency in two samples of children (experiments 1 and 2), and that more errors were made on words with higher DM scores for poor readers. Furthermore, the DM metrics predicted children's number of words read correctly per minute after accounting for estimated Lexile passage scores in a third sample (experiment 3). These results show that after controlling for word frequency (experiments 1 and 2) and estimated Lexile scores (experiment 3) the model including the DM metrics was significantly better in predicting children's word reading fluency both for individual words and passages. While further refinement of this DM measure is ongoing, it appears to be a promising new measure of decodability at both the word and passage level. The measure also provides the opportunity to enable precision teaching techniques, as grapheme-phoneme correspondence profiles unique to each child could facilitate individualized instruction, and text.

Using information-theoretic measures to characterize the structure of the writing system: the case of orthographic-phonological regularities in English

It is generally well accepted that proficient reading requires the assimilation of myriad statistical regularities present in the writing system, including in particular the correspondences between words' orthographic and phonological forms. There is considerably less agreement, however, as to how to quantify these regularities. Here we present a comprehensive approach for this quantification using tools from Information Theory. We start by providing a glossary of the relevant information-theoretic metrics, with simplified examples showing their potential in assessing orthographic-phonological regularities. We specifically highlight the flexibility of our approach in quantifying information under different contexts (i.e., context-independent and dependent readings) and in different types of mappings (e.g., orthography-to-phonology and phonology-to-orthography). Then, we use these information-theoretic measures to assess real-world orthographic-phonological regularities of 10,093 mono-syllabic English words and examine whether these measures predict inter-item variability in accuracy and response times using available large-scale datasets of naming and lexical decision tasks. Together, the analyses demonstrate how information-theoretical measures can be used to quantify orthographical-phonological correspondences, and show that they capture variance in reading performance that is not accounted for by existing measures. We discuss the similarities and differences between the current framework and previous approaches as well as future directions towards understanding how the statistical regularities embedded in a writing system impact reading and reading acquisition.

Modeling and Visualizing the Codevelopment of Word and Nonword Reading in Children From First Through Fourth Grade: Informing Developmental Trajectories of Children With Dyslexia

Developmental studies examining relations between word reading (WR) and decoding in typical and dyslexic populations routinely cut the reading distribution to form distinct groups. However, dichotomizing continuous variables to study development is problematic for multiple reasons. Instead, we modeled and visualized the parallel growth of WR and nonword reading (NWR) factor scores longitudinally in a Grade 1-4 developmental sample (N = 588). The results indicate that while WR and NWR growth factors are highly related (r = .71), the relation between WR and NWR trajectories change as a function of initial WR. Results are interpreted within computational models of dyslexia in which children with dyslexia overfit orthography → phonology relations at the level of the word, limiting the development of sublexical representations needed to read nonwords.

Individual differences in learning the regularities between orthography, phonology and semantics predict early reading skills

Statistical views of literacy development maintain that proficient reading requires the assimilation of myriad statistical regularities present in the writing system. Indeed, previous studies have tied statistical learning (SL) abilities to reading skills, establishing the existence of a link between the two. However, some issues are currently left unanswered, including questions regarding the underlying bases for these associations as well as the types of statistical regularities actually assimilated by developing readers. Here we present an alternative approach to study the role of SL in literacy development, focusing on individual differences among beginning readers. Instead of using an artificial task to estimate SL abilities, our approach identifies individual differences in children's reliance on statistical regularities as reflected by actual reading behavior. We specifically focus on individuals' reliance on regularities in the mapping between print and speech versus associations between print and meaning in a word naming task. We present data from 399 children, showing that those whose oral naming performance is impacted more by print-speech regularities and less by associations between print and meaning have better reading skills. These findings suggest that a key route by which SL mechanisms impact developing reading abilities is via their role in the assimilation of sub-lexical regularities between printed and spoken language -and more generally, in detecting regularities that are more reliable than others. We discuss the implications of our findings to both SL and reading theories.

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.

Variations in the use of simple and context-sensitive grapheme-phoneme correspondences in English and German developing readers

Learning to read in most alphabetic orthographies requires not only the acquisition of simple grapheme-phoneme correspondences (GPCs) but also the acquisition of context-sensitive GPCs, where surrounding letters change a grapheme's pronunciation. We aimed to explore the use and development of simple GPCs (e.g. a ➔ /æ/) and context-sensitive GPCs (e.g. [w]a ➔ /ɔ/, as in "swan" or a[l][d] ➔ /o:/, as in "bald") in pseudoword reading. Across three experiments, English- and German-speaking children in grades 2-4 read aloud pseudowords, where vowel graphemes had different pronunciations according to different contexts (e.g. "hact", "wact", "hald"). First, we found that children use context-sensitive GPCs from grade 2 onwards, even when they are not explicitly taught. Second, we used a mathematical optimisation procedure to assess whether children's vowel responses can be described by assuming that they rely on a mix of simple and context-sensitive GPCs. While the approach works well for German adults (Schmalz et al. in Journal of Cognitive Psychology, 26, 831-852, 2014), we found poor model fits for both German- and English-speaking children. Additional analyses using an entropy measure and data from a third experiment showed that children's pseudoword reading responses are variable and likely affected by random noise. We found a decrease in entropy across grade and reading ability across all conditions in both languages. This suggests that GPC knowledge becomes increasingly refined across grades 2-4.

Predicting Arabic word reading: A cross-classified generalized random-effects analysis showing the critical role of morphology

The distinctive features of the Arabic language and orthography offer opportunities to investigate multiple word characteristics at the item level. The aim of this paper was to model differences in word reading at the item level among 3rd grade native Arabic-speaking children (n = 303) using cross-classified generalized random-effects (CCGRE) analysis. The participants read 80 vowelized words that varied in multiple elements that may contribute to their decodability: number of letters, number of syllables, number of morphemes, ligaturing (connectivity), semantics (concrete vs. abstract), orthographic frequency, root type frequency, and part of speech. Morphological awareness (MA) was included as a person-level predictor. Results of individual models showed that MA, number of letters, number of syllables, number of morphemes, number of ligatures, orthographic frequency, and part of speech were significantly related to the probability of a correct response. However, when all predictors were entered simultaneously, only MA and number of morphemes remained significant. These results underscore the important role of morphology in the lexical structure of Arabic words and in Arabic word reading. Discussion focuses on the role of morphology in Arabic reading and the implications for intervention to improve word recognition in children learning to read Arabic.

The Role of Set for Variability in Irregular Word Reading: Word and Child Predictors in Typically Developing Readers and Students At-Risk for Reading Disabilities

In a quasiregular orthography like English, children inevitably encounter irregular words during reading. Previous research suggests successful reading of an irregular word depends at least partially on a child's ability to address the mismatch between decoded form and stored word pronunciation, referred to as a child's set for variability, and the word's relative transparency, measured here using a spelling to pronunciation transparency rating. Item-level analyses were used to explore the relationship between general child performance on the set for variability mispronunciation task, word specific set for variability (predicting reading of that word), spelling to pronunciation transparency rating, and irregular word reading. Significant predictors included general word reading, general set for variability performance, and item-specific set for variability performance; word frequency and spelling to pronunciation transparency rating; and interaction between word reading and the transparency rating. Results underscore the importance of considering both general and item-specific factors affecting irregular word reading.

Linking Behavioral and Computational Approaches to Better Understand Variant Vowel Pronunciations in Developing Readers

The overarching goal of the new Florida State University/Haskins Laboratory/University of Connecticut Learning Disability (LD) Hub project is to align computational and behavioral theories of individual word reading development more closely with the challenges of learning to read a quasi-regular orthography (i.e., English) for both typically developing (TD) children and, more specifically, children with dyslexia. Our LD Hub adopts an integrated approach to better understand the neurocognitive bases of individual differences in word reading development by specifically examining the experiential (exogenous) and child-specific (endogenous) factors that determine acquisition of orthographic-phonological knowledge at different subword granularities using behavioral and computational modeling. Findings are intended to enrich understanding of the processes that influence individual differences in word reading development in TD and dyslexic children and significantly inform issues of practice (e.g., curriculum, instruction, diagnosis, and intervention). Here, we briefly provide the rationale for the Hub and present findings from the initial behavioral and computational modeling studies.

Development of context-sensitive pronunciation in reading: The case of ‹c› and ‹g›

Writing systems sometimes deviate from one-to-one associations between letters and phonemes, but the deviations are often predictable from sublexical context. For initial ‹c› and ‹g› in English, deviations from the typical /k/ and /g/ pronunciations are influenced by adjacent context (the following vowel, as in center vs. canter) and nonadjacent context (the presence of a Latinate vs. basic suffix, as in gigantic vs. giggling). We conducted two experiments with participants ranging in reading level from early elementary school to university to study the development of context use. Experiment 1 focused on adjacent context, and Experiment 2 also examined nonadjacent context. Use of context developed slowly, and readers at all levels were not as influenced by it as would be expected given the contextual effects in the English vocabulary. We discuss possible reasons for these phenomena and the need to teach children to use context more effectively.

The Role of Statistical Learning in Word Reading and Spelling Development: More Questions than Answers

This special issue bundles a set of eight empirical studies and one review article that explore the role of SL mechanisms (both domain-specific and domain-general) in supporting word reading and spelling development, and vice-versa. In this introduction to the special issue, we worked to summarize the extent to which studies support our hypotheses relating SL to reading and spelling development while also pointing out inconsistencies across studies that require us to refine and rethink our hypotheses.