largely to “hot-house” beginning readers by enabling them to read sooner that they would otherwise, but ultimately no better overall. Consider the question of when to commence reading instruction. The conventional wisdom is that although it is possible to teach many children to read in kindergarten or even in preschool, there is no advantage in doing so because children who are taught to read in 1st grade soon will catch up with those taught to read earlier. Might the same outcome be expected for phonological awareness training? If so, no long-term effects of training are expected.

The results on maintenance of effects of training are presented in Table 9-2 . Negative values for weighted mean are interpreted as dissipation of training effects after treatment ends, whereas positive values are interpreted as enhanced training effects upon follow-up. All of the weighted means were either significantly negative or not reliably different from zero. Clearly, training effects are not magnified over time once training has ended. At best they are maintained or diminish considerably.

Numbers of Children Who Appear to Benefit

Substantial effect sizes, which reflect the average performance of an intervention group relative to a control group, can be obtained even when, for example, a third of the group fails to respond to the intervention at all.

These issues can be illustrated by an intervention study carried out by Torgesen et al. (2001): 60 children with severe reading problems were randomly assigned to two instructional programs. Both programs incorporated principles of effective instruction. They differed in whether articulatory-based cues were used in training phonemic awareness and in amount of decontextualized training in phonemic awareness and phonemic decoding skills. An Auditory Discrimination in Depth (ADD) program provided considerable decontextualized training using articulatory-based cues. An Embedded Phonics (EP) program provided less decontextualized training,

TABLE 9-2 Maintenance of Effects of Training

Outcome

Average Weighted Effect Size

Z

p

Phonemic decoding

-0.148

-1.53

n.s

Word identification

-0.221

-4.66

<0.001

Fluency

0.199

1.24

n.s.

Comprehension

-0.092

-1.05

n.s.

Spelling

-0.154

-3.12

<0.001

Phonological awareness

-0.560

-10.0

<0.001

 

SOURCE: Wagner (2000).



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