Researchers in 17 European countries, with backgrounds in education, psychology, medicine and linguistics, have formed a network to study learning disorders. Dyslexia has been the focus of five years of studies. Several of the study reports are printed in the latest issue of the Journal of Learning Disabilities.
Previous studies have not conclusively proved a causal relationship between early phonological awareness and reading. One problem with studies carried out in the United States and Britain was that phonological awareness was taught while the children were learning to read.
Studies in Scandinavia and Germany avoid this problem because their kindergarten children do not receive formal reading instruction. These studies show that phonological awareness can be successfully developed through training before children learn to read and spell. But researchers do not know whether this explicit training is equally beneficial to all children.
Most previous studies report a rather large variability in training effects — with smaller effects for children scoring in the lowest quartile on the pretest compared to children from the highest quartile. Thirty percent of at-risk kindergarten children in one study showed no measurable growth in phonological awareness skills after an eight-week training program.
Another study identified at-risk children with a family history of dyslexia and gave them 30 minutes of phonological awareness training every day for 17 weeks. This group was compared to similar at-risk children who received no training and to a randomly chosen control group.
When reading performance was measured two years later only 17 percent of the trained group were labeled dyslexic, compared to 40 percent of the untrained at-risk students. Thus, phonological awareness training appeared to reduce the prevalence of dyslexia in this study.
Taken as a group, these studies indicate that phonological awareness training can have positive effects for at-risk children, though the size of the effects varies from study to study.
Phonological training benefits
German researchers Wolfgang Schneider, Marco Ennemoser, Ellen Roth and Petra Kuspert analyzed data from a recent study to determine whether training in phonological awareness works equally well for all groups of preschool children. Researchers trained 191 randomly selected children and compared their performance to that of a randomly selected control group of 155 children who did not receive training.
The children’s scores on the initial pretest of phonological awareness were used to subdivide the children of both groups into at-risk (bottom quartile), average, and above average (top quartile).
Schneider et al. found substantial individual differences in each of the three trained groups, and there were several children in each of the groups who did not benefit much — if at all — from the training. Although most of the children did show positive long-term effects of their training in phonological awareness, the degree of benefit could not be predicted from their initial level of phonological awareness. As a group, however, at-risk children gained the most from training followed by the initially average and advanced children.
To further explore whether the training caused increased achievement, these researchers divided each subgroup into children with high and low training gains and retested them two years later. The findings were the most impressive for at-risk children.
Children with high training gains outperformed children with low gains on most measures of reading and spelling. However, since gains in training did not account for all reading achievement, researchers looked for other factors influencing reading acquisition. Word span (memory for words) was the only other variable that contributed significantly to differences in gains among at-risk children.
Training reduces the risk of dyslexia
There was a large training effect for at-risk children when compared with both untrained at-risk children and the random control group. Pretest differences between at-risk groups were negligible, while both phonological post-test and reading and spelling tests given two years later revealed a large positive effect for training.
Trained at-risk students also outperformed the average control students on all post tests even though the control group was significantly better at pretest. The prevalence of dyslexia (commonly defined in Europe as scoring in the bottom 15 percent in reading and spelling) was much lower among the trained at-risk children than the untrained at-risk children two years after training. Forty percent of the untrained at-risk students were labeled dyslexic at the end of second grade, compared to only seven percent of the trained at-risk group.
Children with initially low metalinguistic skills did benefit from phonological awareness training. The most striking evidence of benefit was the reading and spelling results of trained at-risk children compared to those of the average control group.
The initially at-risk students continued to outperform the control group for two years. These findings indicate that the potential of phonological training may have been underestimated in previous research. Schneider et al. also point out that there is evidence that phonological awareness training complemented by letter-sound training can produce even greater benefits.
Most of the children within each group benefited considerably from the training which yielded long-term effects. The level of phonological awareness prior to training did not predict the size of the effect.
“Kindergarten Prevention of Dyslexia: Does Training in Phonological Awareness Work for Everybody?” Journal of Learning Disabilities, Volume 32, Number 5, September/October 1999, pp. 429-436.
Published in ERN November 1999 Volume 12 Number 8