Monday, February 14, 2011

(2001) Phonemic awareness instruction helps children learn to read: Evidence from the National Reading Panel's meta-analysis

(Ehri, Nunes, Willows, Schuster, & Yaghoub-Zadeh, 2001) Meta-analysis of PA

Words of warning: "Well-designed experiments yielding positive outcomes provide the strongest evidence that PA caused the improvement in reading. Although all of the studies in our database consisted of experiments, some were better designed than others. Studies varied in whether they used treated or untreated control groups. The use of untreated controls receiving no special attention from researchers runs the risk of Hawthorne effects as an explanation for differences favoring the treatment group. Studies varied in whether students were randomly assigned to treatment and control groups, or whether a quasi-experimental design was used in which existing groups were assigned to conditions, or whether students were matched and assigned to conditions. Although random assignment is preferable, researchers may be limited to a quasi-experimental design when classrooms in schools are studied. We examined whether positive effects of PA instruction emerged primarily from the weaker designs or whether effects were strongest in the best designed experiments.”

* IMPORTANT IDEA: Preschoolers use language to communicate, focusing on meaning, not phonological structure. They have little PA and can gain much from PA instruction. Beginning readers have some phoneme  awareness, because making progress in reading requires grapheme-phoneme knowledge - taught in gr 1. PA instruction may contribute to literacy, but may be less effective than early PA instructions. Beyond first grade, PA may be less important than the need to learn spelling patterns in words, so instruction focused on phonemes could be purposeless. 

Quotes with potential (B&vI refers to Bus and van Ijzendoorn, 1999)
The "impact of PA instruction may be greatest in preschool and kindergarten, and may become smaller beyond first grade" (p. 255). In the B&vI (1999) meta-analysis, although all groups profited from PA instruction, preschoolers benefited more than kindergartners or primary school students.

"PA instruction may contribute less to older, normally developing readers, but may make a difference for older children who have failed to make normal progress in reading. Research has shown that disabled readers have poor phonemic awareness, even below that of nondisabled students reading at the same grade-equivalent level (Bradley, Bryant, 1983; Bruck, 1992; Fawcett and Nicholson, 1995). In addition, disabled readers have special difficulty learning to spell (Bruck, 1993). We might expect PA instruction to help in remediating the reading and spelling difficulties of these readers" (p. 255).

"Sounds are ephemeral, short-lived, and hard to grasp, whereas letters provide concrete, visible symbols for phonemes. Thus, we might expect children to have an easier time acquiring PA when they are given letters to manipulate. Also, because letters bring children closer to the task of applying PA in reading and spelling, we would expect transfer to be greater when PA is taught with letters. In the B&vI (1999) study, PA instruction with letters produced larger effects on PA and reading than instruction without letters" (p. 255).

Need to follow this model suggested in B&vI study
"B&vI (1999) obtained only partial support for this. They found that individualized instruction was less effective than small-group instruction for teaching PA, but was more effective for promoting transfer to reading. Replication of this effect with our larger database was considered important."

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