Suzanne M. Adlof
Associate Professor
Doctoral Program Coordinator
Communication Sciences and Disorders
Arnold School of Public Health
University of South Carolina
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Columbia
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Marc Brysbaert
Department of Experimental
Psychology
Ghent University
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Belgium

Kate Cain
Department of Psychology
Lancaster University
Lancaster
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Markéta Caravolas
School Human and Behavioural Science
Bangor University
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Anne Castles
Department of Psychological Sciences & Macquaire Centre for Reading
Macquarie University
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Hugh W. Catts
College of Communication and Information
Florida State University
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Jessica Chan
Faculty of Education
Okanagan School of Education
The University of British Columbia
EME 3145, 1137 Alumni Avenue
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Donald L. Compton
Professor of Psychology and Education
Florida Center for Reading Research
Florida State University
Psychology C234M
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Ashley A. Edwards
Department of Psychology
Florida State University
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Molly Farry‐Thorn
University of Wisconsin‐Madison
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Madison
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Jonathan Grainger
Laboratoire de Psychologie Cognitive
CNRS & Aix‐Marseille University
UMR7290
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France

Nuria Gutiérrez
Department of Psychology
Florida State University
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Lorna G. Hamilton
School of Education, Language and Psychology
York St John University
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York
YO31 7EX
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Sara A. Hart
Department of Psychology
Florida State University
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Tallahassee
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Marianna E. Hayiou‐Thomas
Department of Psychology
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University of York
UK

Anne Helder
Education and Child Studies
Leiden University
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2333 AK Leiden
The Netherlands

Charles Hulme
Department of Education
University of Oxford
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Oxford
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Nenagh Kemp
Room 132, Social Sciences
University of Tasmania
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Panayiota Kendeou
University of Minnesota
Educational Psychology
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Matthew A. Lambon‐Ralph
MRC Recognition and Brain Sciences Unit
University of Cambridge
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Jun‐Ren Lee
Department of Educational Psychology and Counselling
National Taiwan Normal University
Taiwan

Arne Lervåg
Department of Education
University of Oslo
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Feifei Liang
Tianjin Normal University
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Callie W. Little
Faculty of Medicine and Health
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University of New England
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Simon P. Liversedge
School of Psychology and Computer Science
University of Central Lancashire
Preston
Lancashire
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UK

Catherine McBride
Department of Psychology
The Chinese University of Hong Kong
Hong Kong
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Monica Melby‐Lervåg
Department of Special Needs Education
University of Oslo
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0318 Oslo
Norway

Xiangzhi Meng
School of Psychological and Cognitive Sciences
Peking University
Beijing
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Kristina Moll
Department of Child and Adolescent Psychiatry, Psychosomatics and Psychotherapy
Ludwig‐Maximilians‐University of Munich
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80336 Munich
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Sonali Nag
Department of Education
University of Oxford University
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Kate Nation
Department of Experimental Psychology
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Oxford
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Dora Jue Pan
Department of Psychology
The Chinese University of Hong Kong
Hong Kong
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Silvia Paracchini
School of Medicine
University of St Andrews
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St Andrews
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Karalyn Patterson
MRC Cognition and Brain Sciences Unit
University of Cambridge
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Cambridge
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Charles Perfetti
Learning Research & Development Center
University of Pittsburgh
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PA 15260
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Yaacov Petscher
College of Social Work
Florida State University
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University Center
Building C ‐ Suite 2500
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Kathleen Rastle
Department of Psychology
Royal Holloway, University of London
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Egham
Surrey
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Valeria M. Rigobon
Department of Psychology
Florida State University
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Robert Savage
University College London Institute of Education
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London
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Mark S. Seidenberg
University of Wisconsin‐Madison
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Madison
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Margaret J. Snowling
Department of Experimental Psychology
St John’s College
Oxford
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Laura M. Steacy
College of Education & Florida Center for Reading Research
Florida State University
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Rebecca Treiman
Department of Psychological and Brain Sciences
Washington University in St. Louis
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Paul van den Broek
Education and Child Studies
Leiden University
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Richard K. Wagner
Department of Psychology
Florida State University
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Krystal Werfel
Center for Childhood Deafness,
Language, and Learning
Boys Town National Research Hospital
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Sarah G. Wood
Department of Psychology
Florida State University
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Anna Woollams
Division of Neuroscience & Experimental Psychology
The University of Manchester
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Manchester
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Jason D. Yeatman
Graduate School of Education
Stanford University
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Stanford
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Chuanli Zang
Tianjin Normal University
University of Central Lancashire
Preston
Lancashire
PR1 2HE
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Jason D. Zevin
University of Southern California
3551 Trousdale Parkway – ADM 204
Los Angeles
CA 90089‐4019
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Fotena A. Zirps
Department of Psychology
Florida State University
1107 W.Call Street
Tallahassee
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As the eponymous title The Science of Reading suggested, the aim of the first edition of this handbook was to bring together scientific studies of reading into a state‐of‐the‐art review. The preface of that volume stated “The science of reading is mature and healthy as the contributions to this volume make clear.” Our aim in this second edition remained the same – to bring together scientific studies of reading into an updated overview of the field; as we shall see, old questions have been answered and new questions have arisen as understanding of the complexities of reading has deepened, driven by theoretical insights and methodological advances.

Part 1 deals with word recognition processes in skilled reading. This is a natural starting point: Words are the building blocks of reading and without adequate word identification, reading comprehension is compromised. With a review of the skilled system as a backdrop, Part 2 considers the development of word reading. Although knowledge of word recognition processes and their development was already advanced fifteen years ago, each of the chapters in Parts 1 and 2 highlights new findings and research directions. A number of themes emerge, not least a greater recognition of the need to unite theories about development and learning with theories about skilled processing – after all, reading in proficient adults is the product of many years of reading experience that has optimized the reading system to the task in hand. Another important development has been to better understand how morphological structure is represented in written language, and how this is accessed and used during word recognition. Like the mappings between orthography and phonology, morphological information is systematically represented in orthography in ways that reflect graded regularities. Learning to read efficiently requires children to develop a reading system that adequately embodies the distributional information coded by the writing system. In line with this view, several chapters emphasize statistical learning approaches that view skilled reading as the emergent product of interactions between readers and texts.

Word recognition is the front end of skilled processing and is central to learning to read, but much more is required to allow understanding of the texts we read. Part 3 focuses on the complexities of reading comprehension and its development. Key developments since the first edition include an emphasis on the need for greater integration between different levels of enquiry – word recognition, sentence processing, and discourse processing have tended to be different research streams, each with its own traditions, assumptions, and methodologies. While these different approaches have often been considered as separate, these chapters stress that comprehension is multifactorial – not a single entity so much as a product, constructed by multiple cognitive processes operating over a text, in concert with background knowledge. There are important implications for the classroom, not least the observation that reading comprehension might fail for many different reasons.

Part 4 turns to reading in different languages, a field that has burgeoned in recent years. While the science of reading is still dominated by studies in English, reading scientists agree that theories must pay attention to the universal features of reading as well as those that develop from specific experiences with particular writing systems. Here, chapters provide overviews of alphabetic, alpha‐syllabic, and Chinese orthographies, and elsewhere in the book, reference is made to research emanating from different writing systems.

Part 5 considers reading disorders. As in the first edition, there are chapters on both developmental and acquired disorders of reading. In the current volume, there is more convergence between these two strands of research, both noting that selective deficits are rare in developmental as well as in acquired dyslexic populations. Importantly, there is an intimate relationship between reading and language as seen from the perspective of learning to read with a language or hearing impairment as well as in some acquired dyslexias. New to this model is consideration of cognitive models of comorbidity among dyslexia, mathematics disorder, and ADHD, underlining the interconnections between the cognitive and brain systems that underpin reading.

Finally, Part 6 is concerned with aetiology and considers both the biological and social factors that are associated with learning to read. The chapters take us from molecular genetics to the environment provided by parents, classrooms and neighborhoods. They remind us that reading is complex and that to understand it we need to consider genetic influences and their interaction with multiple environmental factors during development. It closes with a detailed review of the neural bases of reading and its development. Neuroimaging methods have expanded since the first edition of the handbook and an important development has been consideration of neuroimaging data in the context of both cognitive and developmental theories.

Although advances in knowledge are expected in an active research field, the rise of The Science of Reading as a movement aiming to use empirical evidence from scientific studies of reading to inform education and teacher knowledge, and to translate from the laboratory to the classroom was unanticipated by the first edition of this handbook. The International Literacy Association defines the Science of Reading as “a corpus of objective investigation and accumulation of reliable evidence about how humans learn to read and how reading should be taught.” Not every reading scientist is working on developmental issues and even fewer focus on the translation of research findings to practice. We believe it is important that research continues at a basic and “laboratory level.” However, knowledge gained from basic science can and should be used to inform instructional approaches – and this is the difficult part. Reading practitioners have an important role to play in partnership with researchers by providing vital expertise about classrooms, cultures, and contexts, factors often downplayed in cognitive models. It is only when these are understood that it will be possible to implement evidence‐based programs of literacy instruction that are sustainable in communities and cultures around the world.

As this second edition is published, it is tempting to forecast what developments might feature in a hypothetical third edition. Reading and writing go hand in hand, but it remains the case that scientific studies of reading are far more common than scientific studies of writing, and those studies of writing that exist focus heavily on spelling and much less so on sentence or discourse level writing. Learning to be literate demands that children write effectively as well as read, and there are theoretical reasons to consider the production demands of writing as critical to comprehension. We hope in the coming years that there will be more work on the science of writing and that this will be integrated with studies of reading.

We also predict more research that connects issues in learning to read with those studied in the context of skilled reading, both in terms of word reading and comprehension processes. There is certainly room for more theoretical connection, and for methodological and statistical approaches to be shared, including the exciting developments that will enhance our understanding of the genetic and neural underpinnings of reading. Individual differences in reading are already well‐represented in this edition. Nevertheless, important questions remain, not least when considering the role of linguistic, cultural, and contextual influences in the home and school environment. We also predict greater awareness of individual differences in adults.

Finally, as research connects across the lifespan, we might also consider the fate of people who leave school with low levels of literacy. Even in high‐income countries, approximately 20% of 15‐year‐olds do not attain the levels of literacy needed to allow them to participate effectively in life. These individuals are underrepresented in scientific studies of reading, and arguably too in terms of evidence‐informed adult education and support in the community.

We thank all of the authors of this handbook who have given selflessly of their time to complete these chapters during the COVD‐19 pandemic. We have learned a great deal from the experience of editing and discussing their contributions. We thank Jenny Diment and Rhianna Watt for their invaluable support at all stages of the editorial process.

Word recognition is the foundation of reading; all other processes are dependent on it. If word recognition processes do not operate fluently and efficiently, reading will be at best highly inefficient. The study of word recognition processes is one of the oldest areas of research in the whole of experimental psychology (Cattell, 1886). In the opening chapter of this second edition of The Science of Reading, Perfetti and Helder provide a comprehensive overview of recent advances in the study of reading, with particular emphasis on skilled reading in adults. This chapter sets the stage for the chapters that follow. Guided by the analogy of reading as a rapidly moving stream, they use the Reading Systems Framework to show how different knowledge sources, including critical lexical knowledge, underpin the processes that take the reader from word identification to comprehension (and how these may be disrupted in reading disorders). In so doing they consider the range of methodologies that have been used to investigate reading processes, including neurophysiological measures and brain imaging, emphasizing that computational methods and language corpora together add precision to theoretical proposals.

The science of reading should not be specific to one language or one writing system. Perfetti and Helder highlight not only universals in reading processes, but also some of the patterns of variation found across the world’s orthographies. Together these suggest that writing systems evolve to accommodate properties of the languages they represent. Regarding reading acquisition they note that “…effective experience [in reading] in which children read words successfully and achieve comprehension—is the only certain path to establishing rapidly accessible orthographic representations.”

In the first edition of the book, two models that framed much subsequent research were considered: the dual‐route model and the connectionist framework, respectively, by Coltheart (2005) and Plaut (2005). In this edition, Seidenberg, Farry‐Thorn and Zevin consider theoretical models of word recognition with a critical appraisal of computational models of reading aloud. Reminding us that feedback between empirical data and theoretical models is a powerful way of investigating cognitive processes and generating hypotheses, they argue that the standard of proof required is high – that the behavior of the model should align with that of the reader. In addition, the model should accommodate data from multiple languages and different writing systems. Seidenberg et al. focus on learning to read in English where a significant challenge is to model reading across words that vary in the consistency of their spelling‐sound correspondences – an issue that can be addressed by including mappings between semantics, orthography and phonology.

One advantage of connectionist models is that as they learn, they become sensitive to orthographic consistencies inherent in the writing system and the knowledge that accrues is used to feedback and further refine representations of that knowledge. Echoing the sentiments of Perfetti and Helder, computational models can guide reading curricula and make recommendations for both explicit instruction and implicit learning via reading experience. Advances in computational models of learning to read are likely to provide an important future direction with important educational implications.

In the first edition of this book, Lupker (2005) and Van Orden and Kloos (2005) reviewed a large body of experimental evidence concerned with how adults recognize printed words. Any complete model of word recognition has many phenomena to explain: that people perceive letters more efficiently when they are embedded in words than presented in isolation, that high‐frequency (i.e., more familiar) words are recognized more easily than less familiar words, and various patterns of priming. One conclusion that emerged powerfully from these earlier reviews was the need for interactive models in which activation of orthographic and phonological information reciprocally influence each other. In this second edition, three chapters on skilled visual word recognition continue and expand on this theme. Grainger begins by discussing the orthographic processes that mediate between vision and language when translating letters into word representations. He argues that words are the basic units of reading, and that letters are the basic units of words. Careful experimentation has shown that skilled readers use abstract information about the identity and position of letters to recognize words, and that processing is cascaded and interactive. Beyond word identification, he suggests that sentence reading – or at least the interface between whole‐word representations and the sentence – is governed by mechanisms that share the same general characteristics, namely processing that is interactive, cascaded, and performed at least partly in parallel. These allow the syntactic and semantic representations required for sentence comprehension to be activated rapidly from orthography. Grainger notes that word recognition and sentence processing have tended to be investigated within two independent lines of research, a theme echoed in several chapters of the handbook. Future work needs to better integrate evidence across words, sentences and texts to fully understand how reading happens.

While Grainger focuses on orthographic processes in skilled reading, Brysbaert tackles the role of phonology. Taking a historical perspective, he describes how researchers have defended very different positions over the years, from full phonological mediation between print and meaning through to no phonological involvement at all. It is now widely accepted that phonology plays a central role in skilled word reading. In alphabetic writing systems, phonology is particularly important in the early stages of reading development, when the ability to assemble the phonological form of an unknown word is foundational. Brysbaert’s review makes clear that phonology continues to be engaged automatically in skilled word reading. At least in alphabetic writing systems, orthographic and phonological processes jointly contribute to visual word recognition and this is achieved via coding interactions in the brain. Brysbaert closes by considering how extant models of word recognition accommodate the central role of phonology.

Since the first edition of the handbook, word recognition research has expanded to include detailed consideration of morphology. This progress is reviewed by Rastle in the context of processing English. Morphemes are defined as the smallest unit of meaning and are either stems or affixes. The majority of words in English (and many other languages) are built from morphemes. Although there is a tendency to think of the relationship between print and meaning as largely arbitrary, morphological structure represents an important interface between orthography and meaning. Rastle provides many examples of graded systematicity in the mappings between spelling and meaning at the level of morphemes. Skilled readers are highly sensitive to these “islands of regularity,” many of which are preserved in the writing system, often at the expense of maintaining regularity between spelling and sound. This means that morphological information is highly visible in the writing system. Rastle reviews evidence showing that morphological information is activated by skilled readers during the course of visual word recognition and discusses how different models of word recognition can capture these influences; like earlier chapters in this section, she emphasizes the value of computational approaches. Rastle reminds us that the goal of reading words is to rapidly compute their meaning, and therefore that the goal of learning to read is to develop a system that maps orthography to meaning quickly, directly, and accurately. Although morphological effects in skilled word recognition are well documented, far less research has considered how morphemic knowledge becomes represented in the reading system as children learn to read. Rastle identifies this as an important direction for future work, highlighting the likely role that reading experience plays as the substrate for establishing probabilistic mappings between orthography and meaning.

References

1. Cattell, J. M. (1886). The time taken up by cerebral operations. Mind, 11, 220–242.
2. Coltheart, M. (2005). Modeling reading: The dual‐route approach. In M.J. Snowling & C. Hulme (Eds.), The science of reading: A handbook (pp. 6–23). Blackwell Publishing. https://doi.org/10.1002/9780470757642.ch1.
3. Lupker, S. J. (2005). Visual word recognition: Theories and findings. In M.J. Snowling & C. Hulme (Eds.), The science of reading: A handbook (pp. 39–60). Blackwell Publishing. https://doi.org/10.1002/9780470757642.ch3.
4. Plaut, D. C. (2005). Connectionist approaches to reading. In M.J. Snowling & C. Hulme (Eds.), The science of reading: A handbook (pp. 24–38). Blackwell Publishing. https://doi.org/10.1002/9780470757642.ch2.
5. Van Orden, G. C., & Kloos, H. (2005). The question of phonology and reading. In M.J. Snowling & C. Hulme (Eds.), The science of reading: A handbook (pp. 61–78). Blackwell Publishing. https://doi.org/10.1002/9780470757642.ch3.