A Longitudinal Study of Dyslexia Bergen's Multivariate Study of Children's Learning Disabilities Hans-Jorgen Gjessing Bjorn Karlsen A Longitudinal Study of Dyslexia Bergen's Multivariate Study of Children's Learning Disabilities With 23 Figures Springer Science+Business Media, LLC Hans-JOrgen Gjessing, Ph.D. Professor, Department of Educational Psychology University of Bergen 5007 Bergen, Norway Bjorn Karlsen, Ph.D. Professor Emeritus Sonoma State University Rohnert Park, CA 94928 USA Library of Congress Cataloging-in-Publication Data Gjessing, Hans-J~rgen. A longitudinal study of dyslexia : Bergen's multivariate study of children's leaming disabilities / by Hans-J~rgen Gjessing & Bj~rn Karlsen. p. cm. 1. Dyslexia-Norway-Longitudinal studies. 2. Dyslexic children Norway-Longitudinal studies. 3. Bergenprosjektet. 1. Karlsen, Bj~m. II. TitIe. [DNLM: 1. Bergenprosjektet. 2. Dyslexia-in infancy & childhood. 3. Longitudinal Studies. WM 475 G539L] RJ496.A5G54 1989 618.92'8553'009481-dc 19 DNLMIDLC for Library of Congress 89-4127 CIP PPrriinntteedd oonn aacciidd--ffrreeee ppaappeerr.. © 1989 by Springer Science+Business Media New York Originally published by Springer-Verlag New York Ine. in 1989 Softcover reprint ofthe hardcover lst edition 1989 AII rights reserved. This work may not be translated or copied in whole or in part without the written permission ofthe publisher (Springer Science+Business Media, LLC), except for brief excerpts in connection with reviews or scholarly analysis. Use in connection with any form of information storage and retrieval, electronic adaptation, computer software, or by similar or dis similar methodology now known or hereafter developed is forbidden. The use of general descriptive names, trade names, trademarks, etc. in this publicat ion, even if the former are not especially identified, is not to be taken as a sign that such names, as understood by the Trade Marks and Merchandise Marks Act, may accordingly be used freely by anyone. Typeset by Publishers Service, Bozeman, Montana. 9 8 7 6 5 4 3 2 1 ISBN 978-1-4612-6452-1 ISBN 978-1-4419-8704-4 (eBook) DOI 10.1007/978-1-4419-8704-4 Preface Psychological and educational researchers in the Scandinavian countries have cooperated in a research effort relating to children's learning disabilities for more than a decade. Support has come from the federal governments and other funding agencies in Norway, Sweden, and Denmark through the Secretariat for Scan dinavian Cultural Cooperation. A number of independent studies have already been published, dealing with various aspects oflearning disabilities in the literacy skills of reading and writing. The largest and most comprehensive study was the Bergen Project, a longitudi nal study of an entire cohort of children, with special emphasis on those who developed specific learning disabilities in reading and writing (dyslexia). These dyslexic children were studied, diagnosed, and treated over a period of nine years, along with various control and comparison groups, which included a large subgroup with general learning disabilities (retarded). The Bergen Project involved the collection of voluminous data. The children were identified by means of special diagnostic tests and treated using remedial materials and techniques that had been developed to deal with various types of dyslexia. The ophthalmology team not only tested the children, but they also prescribed and provided glasses, and even performed surgery when necessary. The pediatric neurologists did general pediatric and neurological examinations, following up many of the cases with EEGs and CT (computerized tomography, brain x-rays). Three book length reports on the Bergen Project have been published, along with some articles and, of course, the tests and instructional materials. But these reports have been in Norwegian and thus not available to a broader audience. This book remedies that situation: it is a final report of the entire project in English. Since the project entailed literally hundreds of variables, and since a major thrust of the project was to study how all these variables correlated and interacted, the statistical work-up of the data became quite complex. The data are reported in various tables, but the interpretations in the text are written to reach the large number of people who are vitally interested in this topic. This includes educators, psychologists, counselors, various medical specialists, and other researchers. Part of the excitement of bringing this report to an international audience is to present the culmination of several decades of work by Professor H.-J. Gjessing at vi Preface the University of Bergen in Norway. Out of his work has evolved the theory that we are dealing with several types of dyslexia. This research supports the notion that such types can be identified. Of even more importance is the fact that individuals exhibiting the different types must be taught differently; teaching techniques that may be beneficial for some dyslexic children may be detrimental to others. This research project was made possible through the assistance and cooperation of a large number of people over a period of many years: the administration of the Bergen public schools, teachers, special education specialists, school psycholo gists, and school health services. We must also thank the many who assisted in the data collection: the Departments of Ophthalmology and Pediatrics at Haukeland Hospital (the University Medical School), the Bergen Hearing Institute, and the University Psychology Faculty (especially the Institute for Psychometrics). Our deepest appreciation is also extended to the hundreds of children who participated and to their parents who helped in so many ways. I personally became involved in this project at an early stage, having done my Ph.D. study in this field and having developed diagnostic reading tests in the United States. Later on, I worked full time on this project for 6 months in Bergen in 1985 and have been solely responsible for all translations and the adaptation of the material for an English-reading audience. Bjorn Karlsen Contents Part I Introduction .. .. .. .. ...... ...... ...... ..... ....... .... 1 1. Purposes and Design of the Study; Organization of the Book H.-1. Gjessing . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3 2. Description of Earlier Reports on the Bergen Project H.-1. Gjessing . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8 3. Methodological Issues in Dyslexia Research H.-1. Gjessing . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15 Part II School Learning Disabilities . . . . . . . . . . . . . . . . . . . . . . . . . . . . 29 4. School Achievement R. Solheim. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 31 5. Socioemotional Characteristics R. Solheim. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 36 6. Cognitive and Achievement Characteristics H.-1. Gjessing and H.D. Nygaard. . . . . . . . . . . . . . . . . . . . . . . . 59 Part III Theoretical and Clinical Foundation of This Study of Dyslexia ...... ..... ... ... ..... .... .. .. . 67 7. Overview of Research on Reading and Dyslexia H.-1. Gjessing and B. Karlsen. . . . . . . . . . . . . . . . . . . . . . . . . . . 69 8. Dyslexia Models and Theories H.-1. Gjessing and B. Karlsen. . . . . . . . . . . . . . . . . . . . . . . . . . . 86 9. Function Analysis of Literacy Behavior H.-1. Gjessing . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 106 Part IV Results of the Study of Dyslexia and Dyslexia Types . . . . . .. 127 10. Descriptive Analysis of the Entire Dyslexia Group H.-1. Gjessing and H.D. Nygaard . . . . . . . . . . . . . . . . . . . . . . .. 129 viii Contents 11. Multivariate Analyses of Clinical and Statistical Groupings H.-J. Gjessing and H.D. Nygaard. . . . . . . . . . . . . . . . . . . . . . .. 153 12. Eye Examinations H. Aasved . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 192 13. Neurological Examinations P. E. Waaler, K. Helland-Hansen, H. Miljeteig, 0. Opshaug, J. L. Larsen, H. Bruland, and L. lrgens . . . . . . . . . . . . . . . . . .. 210 14. Growth and Efficacy Data: Results of the Total Experimental Program H.-J. Gjessing and H.D. Nygaard . . . . . . . . . . . . . . . . . . . . . . .. 227 Part V The Bergen Project's Contribution to Research And Its Applied Educational and Clinical Value . . . . . . . . . . . .. 277 15. Summary, Conclusions, and Discussion of the Entire Project H.-J. Gjessing . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 279 Appendix: Sample Selection Procedures and Grouping of Pupils H. D. Nygaard . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 309 Index. . . . . . . . . . . . .. . . . . . . . . . . . . . . . . . . . .. . . .. . . . . . . . . . . . . . . .. 345 Part I Introduction CHAffER 1 Purposes and Design of the Study; Organization of the Book H.-J. Gjessing The Bergen Project was a longitudinal research and developmental study of primary grade children with severe school learning disabilities. It was carried out in the elementary schools of Bergen, Norway, beginning in 1977. Its theoretical goal was the development of a research strategy in which observations and assess ments of personal and environmental factors are based more on real life functions and processes than on quantitative scores and products. The Bergen Project was actually part of a coordinated set of studies of learning disabilities carried out in the Scandinavian countries of Norway, Sweden, and Denmark. It was sponsored, in part, by the Scandinavian council of ministries (Nordisk Ministerrad). This report deals exclusively with the Bergen Project, which was by far the largest and most comprehensive study of learning disabili ties carried out in the Scandinavian countries. Bergen is the second largest city in Norway, having a population of about 250,000. It is located on the west coast and is the main center for higher educa tion in this area. Because of its location, much of its commercial activity relates to the sea - shipping, fishing, and the exploitation of the North Sea oil fields. The population is quite homogeneous and also very stable. This stability is exempli fied by the attrition rate of 3% in this longitudinal study. Objectives The main objectives of the Bergen Project can be summarized as follows: 1. Describe and analyze the development of an entire regional population of children entering school in a given year with regard to social, emotional, cognitive, and achievement characteristics. 2. Develop procedures for classroom observation and assessment that will iden tify those learning and behavior characteristics that affect school achievement in the primary grades. 3. Explore a system of individual assessment of children's reading and writing characteristics. 4 H.-J. Gjessing 4. Increase knowledge about the many factors, characteristics, and problems involved in school learning problems, in particular underachievement, spe cific reading and writing disabilities, socioemotional problems, visual dys functions, and neurological problems. 5. Develop a set of flexible instructional materials geared to each child's charac teristics, problems, and needs. 6. Improve insight and psychological understanding by teachers and other pro fessionals into the nature and effect of children's school learning difficulties. 7. Develop guidance procedures that will result in better self-insight and under standing of learning difficulties by the children themselves, their parents, and their teachers and in more constructive and psychologically sound channeling of parental efforts to help the children. 8. Develop fairly simple professional, administrative, and financial programs that can be incorporated into a school's long-range planning and that fit the school's resources. 9. Collect, coordinate, and evaluate results and experiences from the other Scan dinavian countries that participated in this series of research projects. Research Population The Bergen Project encompassed every child who entered first grade in the pub lic elementary schools in Bergen in the fall of 1977 , including children with mild mental retardation. This population numbered over 3,000 in 69 schools. Children who attended special schools, such as those with severe mental retardation or with extreme disorders of vision or hearing, were not included for practical rea sons: we wanted to concentrate on the special and remedial education offerings of the regular elementary school. On the other hand, because of new philosophi cal and organizational trends (Gjessing, 1969) relating to integration of the mildly handicapped into ordinary schools, research data on such children were sorely needed. The study covered the first four years of schooling; a final follow-up was done when the children were in the ninth grade. Initial screening tests were administered in the fall of 1977 at the beginning of first grade and repeated in the fall of 1978 at the beginning of second grade. Similar tests were given at the end of grade 3, beginning of grade 4. Although extensive data were gathered on the entire cohort, the main emphasis of the project was the children who developed learning difficulties. These chil dren were divided into separate target groups: those with specific learning dis abilities, referred to in the study as dyslexics, and those with general learning problems ("retarded"). The dividing line between the two groups was not always clear. ("Dyslexia" is defined and discussed in Part III; "retarded" is defined and discussed at some length in the Appendix. These two groups make up about 75% of all children who receive some form of special or remedial education in Bergen.)