Educators try to identify children with reading disabilities as soon as possible in the primary grades. But, there is one group of children that does not begin to display reading disabilities until the fourth grade. Another group of children fluctuates significantly in reading ability in the early grades so that they might not be identified as at-risk if they were only evaluated in kindergarten.
In a study of the “fourth-grade slump” published in the Journal of Learning Disabilities, researchers estimate that the prevalence of late-emerging reading disabilities is between 36-46%. Researchers conducted a longitudinal, retrospective study of fourth grade students with reading disabilities to 1) examine the trajectory of reading development for children who had been followed since kindergarten and 2) examine patterns of performance on measures of skills relevant to reading.
Three sub-groups of students
The researchers found three distinct subgroups of students with reading disabilities in fourth grade:
• Poor readers — Students who scored below the 25th percentile on the Wide Range Achievement Test, third edition (WRAT-3; Wilkinson, 1993) Reading subtest in each year of the study;
• Borderline readers — Students whose scores fluctuated between the 25th and 35th percentiles from kindergarten through third grade; and
• Late-emerging reading disability — Students whose performance was above the 35th percentile in three or more years between kindergarten and Grade 3.
The study included 44 children in Grade 4 from 18 schools in one school district in a small city in Western Canada. Twenty-two of the children were classified as having reading disabilities (RD) in Grade 4 with the remaining 22 classified as typical readers. All of the children were participants in a larger longitudinal study that began in kindergarten and included all of the students in the school district.
There is no consistent definition of reading disability or below-average reading ability in studies of the subject. For this study, researchers classified children as having a reading disability in Grade 4 if their performance on the WRAT-3 Reading subtest, was at or below the 25th percentile.
Performance across subgroups
Children were classified as typical readers if they were at or above the 30th percentile. In the study, each student from the reading disability group was matched with a student who had the same reading score in kindergarten, but was classified as a typical reader in Grade 4. The matched student was the same age, in the same classroom and of the same gender as the student with RD. By the end of Grade 4, the RD group had a mean percentile score of 17.64 on the reading subtest compared with 59.24 for the typical readers.
The researchers found that the RD groups performed differently in the battery of tests they were given to assess skills. In addition to the WRAT-3 tests, other tests included the Woodcock-Johnson Reading Mastery Test-Revised to test word identification and word attack; the Rosner Auditory Analysis Test; In Working Memory for Words; and the Stanford Diagnostic Reading Test
One question about the fourth-grade slump is whether there is a delay in the disability or merely a delay in educators identifying the disability. In this study, the researchers found that late-emergers did in fact perform well on tests until the third and fourth grades. Word-reading skills for students with late-emerging RD did not fall below the 25th percentile until Grade 4.
A possible explanation for the late-emerging disability is that in the earlier grades these children could recognize high-frequency words. However, a combination of underdeveloped phonological skills and increased complexity of word reading made reading a much greater challenge by Grade 4.
“It is possible that the phonological skills of LRD group children were developed enough to achieve in the early primary grades, but not sufficient for the increasing language and reading demands in third and fourth grades,” the researchers say.
An alternative explanation, write the researchers, is that the students mastered the fundamentals of decoding in their early primary years, but had difficulty when the words became more phonologically and morphologically complex.
Children who had a late-emerging disability did in fact show a decrease in phonological processing skills in Grades 3 and 4, performing lower on the WRMT-R Word Attack subtest than typical readers. They also performed lower on the one-minute pseudo-word reading test and on the WRAT-3 Spelling subtest and there was significant variability in their performance on reading comprehension tests.
By contrast, the students identified as poor readers consistently performed lower than all other groups over five years on word reading, phonological processing, reading comprehension and spelling. They performed below the 15th percentile for the five years of the study. The children in the borderline group had a mean WRAT-3 Reading score at the 10th percentile, but moved up to the 34th percentile in Grade 1. By Grade 4, their mean score was at the 20th percentile.
The researchers conclude that their finding highlights the need for ongoing assessment of children’s reading acquisition and achievement not just in kindergarten, but throughout the early years of elementary school.
“Retrospective Analyses of the Reading Development of Grade 4 Students with Reading Disabilities”, by Orly Lipka, Nonie K. Lesaux, and Linda S. Siegel, Journal of Learning Disabilities, July/August 2006, Volume 39, Number 4, pps 364-378.
Published in ERN September 2006 Volume 19 Number 6