Handbook of Learning Disabilities.

EDITED BY H. LEE SWANSON, KAREN HARRIS, AND STEVE GRAHAM

Lee Swanson, Karen Harris, and Steve Graham have masterfully accomplished a task of Herculean proportions. The recent Handbook of Learning Disabilities (LD) is an edited compendium comprised of contributions from over 55 of the leading scholars involved in LD research. Contributing authors were charged with reviewing the major theoretical, methodological, and instructional advances that have occurred in our field over the last 20 years. Most would agree that to be of maximum utility, the content in these areas would have to be organized in a framework that allows for reasonable accessibility. In this important respect, the editors have succeeded. The chapters in the text are neatly organized into five logically sequenced areas: Foundations and Current Perspectives, Causes and Behavioral Manifestations, Effective Instruction, Formation of Instructional Models, and Methodology.

There is something for everyone in this effort. Several of the chapter topics (e.g., genetic influences on reading and writing disabilities, self-concept, memory difficulties) are purposefully narrow and provide depth for those who wish to explore specific issues. Other chapters' topics (e.g., basic cognitive processes and reading disabilities) tend to be broad and more expansive. Finally, there is a series of topics that can best be viewed as foundational (e.g., history of the field, service delivery, law), in that they provide the reader with an integrative summary, or deep background, on prevailing issues in the field. In total, the volume represents the major aspects of the LD field, more information that any single professional may need at any one time. However, the knowledge contained in the text will serve readers well as they seek information over time and across projects, and as they encounter challenging situations. As it is impossible to adequately review the individual contributions to the Handbook, we will summarize each of the five sections and highlight chapters and topics that are particularly noteworthy.

Foundations and Current Perspectives

In the first chapter of this section, the editors provide a useful advance organizer; in addition to summarizing the major topics by chapter and author, they offer guiding questions by section. This is an organizational support that readers may wish to consult prior to reading (or rereading) a particular chapter or section of the book. The opening chapter is followed by several foundation topics such as a brief history of the field, recent research on classification, definition, and identification of LD, and LD and the law. While one could argue that history, law, and certain aspects of service delivery are best not presented in isolation from one another, each of these chapters delivers a strong integration of the factors that have shaped, and continue to influence, our field. For example, Hallahan and Mock, in their all too brief History of LD chapter observe that although it is difficult to predict precisely how our field will progress, it is clear that our rich and varied history will direct future events. Kavale and Forness, in their thoughtful, yet sobering, LD as a Discipline chapter conjecture how this future is developing. Specifically, they posit that we are at a point where the politics and science of the field are often at cross-purposes and that students identified through the political avenues of the LD discipline barely resemble the descriptions typical of the scientific side of the discipline. The authors' observation that a more unified discipline with reduced tensions between these two perspectives may have the potential to solve some of the more vexing issues (e.g., definition) facing our field is instructive. This section of the Handbook concludes with Gersten and Baker's comprehensive review of the special needs of English-language learners with LD and Zigmond's insightful contribution regarding service delivery alternatives. Although the title of the Zigmond chapter indicates that we are searching for the most effective service delivery model, the author cautions that we must remain sensitive to the individual needs of students when considering service delivery alternatives. Until we are ready to accept that a particular setting is good for some and not others, we will not get beyond equivocal research findings.

Causes and Behavioral Manifestations

The second section of the Handbook addresses issues and research associated with causation and behavioral manifestation. The nine chapters in this section cover a wide range of topics. Particularly noteworthy is Siegel's instructive overview of the five cognitive processes involved in the development of reading and the consequences of students having problems with those processes. This is an excellent chapter for those wishing to review the basic elements involved in the acquisition of reading. Also noteworthy are Swanson and Saez's review of the role of working memory in cognitive process and academic performance, and how deficits in these areas contribute to difficulties in reading, mathematics, and writing. For those interested in specific areas of inquiry, there are individual chapters focusing on LD in arithmetic, self-concept, and the relationships among language processes and reading abilities/disabilities. In contrast to these more applied topics, several basic areas of research are presented in chapters on the association between rapid automatized naming and reading disabilities, the "gene-to-brain-to-behavior" approach and the link between LD and ADHD, and the neurological correlates of reading disabilities. With a heavy emphasis on biophysical explanations of LD, these chapters may not be easily accessible to all readers due to the technical nature of their content.

Effective Instruction

What constitutes effective instruction for students with LD is documented in the third section of the handbook. Six chapters consolidate research on strategies that have had a significant impact on individuals with disabilities in reading, writing, mathematics, science, and/or social studies into well-organized reviews. Still it bears mentioning that many of the strategies cited as effective are presently under investigation and that the database can best be characterized as still evolving. Moreover, lack of clarity regarding definitions and terminology may limit the generality of some findings. With respect to reading difficulties, Lovett, Barron, and Benson present methods for remediating word identification and decoding difficulties, whereas Williams emphasizes the teaching of text structure to improve comprehension. To prevent disabilities with written expression, Berninger and Amtmann focus on handwriting and/or spelling needs and technological advances that may address them. Graham and Harris emphasize instruction in self-regulated strategy development to enhance the writing skills of those with LD. Fuchs and Fuchs' dissection of the stages of mathematical problem solving is particularly useful for educators, and their call for explicit instruction to increase metacognition is an important theme. They recognize unique patterns of needs for those with mathematical disabilities alone and those with both mathematical and reading disabilities, theorizing that students with both disabilities may have a greater difficulty with mathematical problem solving than those with only a mathematical disability. In the areas of science and social studies, Scruggs and Mastropieri differentiate between child-centered, constructivist approaches that encourage students to learn by doing themselves versus textbook-led instruction that requires memorization of verbal information and is an area of difficulty for students with LD. A wide range of specific strategies (e.g., processing strategies, mnemonic strategies, peer tutoring) that have helped students learn material in science and social studies are highlighted.

Formation of Instructional Models

Instructional models for teaching persons with LD are the focus of the five chapters in the fourth section of the Handbook. Models range from instruction in basic skills to methods for enhancing higher-order thinking and include direct instruction, curriculum-based instruction, cognitive strategy instruction, cooperative learning, and the sociocultural approach to instruction. Regarding direct instruction, Adams and Carnine note that many students with LD have learned reading, language, math, writing, spelling, and cursive writing through direct instruction. Thus, whether comparing effect sizes between elementary- and secondary-level students, in reading or math, on norm-referenced or criterion-referenced assessment instruments, a sizable effect on performance is found when direct instruction is employed. Fuchs, Fuchs, McMaster, and Al Otaiba note that the dual-discrepancy approach used in curriculum-based measurement (CBM), a method that enables performance and growth comparisons between target students and their typically achieving peers, allows for early identification of students requiring intervention. In a review of cognitive strategy instruction, Wong, Harris, Graham, and Butler caution that the benefits of this approach are of limited use to students with LD if the metacognitive components of planning, doing, monitoring, and critiquing are not emphasized in the instruction of a specific strategy. Although it is a very popular approach to instruction, Jenkins and O'Connor warn that the impact of cooperative learning on the performance of students with LD remains uncertain. While subjective teacher report data suggest that this is a positive practice for students with LD, there are far too few studies that have addressed this area, and those that have been completed have had mixed results. Finally, Englert and Mariage emphasize the importance of collaboration for persons with LD following a sociocultural model. Similar to the application of cooperative learning, the limited amount of research employing this approach to students with LD precludes any firm generalizations.

Methodology

The final section of the Handbook contains five chapters that address the various methodologies used in LD research. These are particularly important contributions in that they look at the validity of the findings that are used to inform practice and policy. Abbott et al.'s overview of data management systems as well as exploratory and confirmatory methods of analysis is much too abbreviated. However, Schumaker and Deshler's overview of designs for applied educational research is replete with useful descriptions of the full range of experimental alternatives available to school-based researchers and should be required reading for all who seek to engage in such activities. The section also contains balanced chapters on both the uses and shortcomings of cluster analysis and the strengths and limitations of functional brain imaging. The section concludes with MacArthur's chapter on the contributions of qualitative research to the field. Of particular interest is how qualitative research allows for an insider's (i.e., those who have the disability) view of LD as well as detailed case studies of service delivery alternatives such as inclusion.

Although we have reviewed several of the more notable parts of this effort, it is clear that this Handbook is more that just a collection of contributions. Putting aside any quibbles with the placement and order of some chapters, as well as the extent of coverage in certain chapters, this highly organized resource is an awe-inspiring accomplishment that speaks well for our professionalism, work ethic, tenacity, and commitment to children.

Given the range of topics presented and the extensive nature of research included in the chapters, it is clear that the field of LD is diverse and multifaceted, and it is comforting to know that exceptional scholars are investigating the multiplicity of challenges that are associated with LD. Conversely, the wide range of topics and research associated with LD reflects a major challenge that we must continue to address: With such diversity of topics, views, and research interests, we must find ways to integrate all of this excellent, relevant research into a message that policy makers and the general public can access, understand and, ultimately, apply. As illustrated in this Handbook, we have made outstanding progress in a number of critical areas and we have the potential to improve considerably the lives of persons with LD. Now, we must ensure that the results of these efforts are routinely put in the hands of those who can make the improvements for the students who need them.

Requests for reprints should be addressed to: Michael S. Rosenberg, Department of Special Education, 100 Whitehead Hall, 3400 N. Charles St., Baltimore, MD 21218.

MICHAEL S. ROSENBERG, Ph.D., is professor, Department of Special Education, Johns Hopkins University. LAURA R. B. BROUGHTON is a doctoral student, Department of Special Education, Johns Hopkins University.