Phonological Awareness and Early Reading: A Meta-Analysis of Experimental Training Studies

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NICHCY’s Structured Abstract 53 describes the following:

Title | Phonological Awareness and Early Reading: A Meta-Analysis of Experimental Training Studies

Author | Bus, A.G., & Van Ijzendoorn, M.H.

Source Journal of Educational Psychology, 91, 403-414.

Year Published | 1999

In a quantitative meta-analysis, the effects of phonological awareness training on reading were shown. In a homogeneous set of U.S. studies with a randomized or matched design, the combined effect sizes for phonological awareness and reading were d = 0.73 (r = 0.34, N = 739) and d = 0.70 (r = 0.33, N = 745), respectively. Thus, experimentally manipulated phonological awareness explains about 12% of the variance in word-identification skills. The combined effect size for long-term studies of the influence of phonological awareness training on reading was much smaller, d = 0.16 (r = 0.08, N = 1,180). Programs combining a phonological and a letter training were more effective than a purely phonological training. Furthermore, training effects were stronger with posttests assessing simple decoding skills than with real-word-identification tests. In sum, phonological awareness is an important but not a sufficient condition for early reading. (PsycINFO Database Record (c) 2005 APA, all rights reserved)

Phonemes are the smallest units of meaningful sound in spoken language. Sometimes a phoneme is a single letter, such as “t” or “s.” Other times a phoneme is a combination of letters that make a distinct sound, such as “th” or “sh.” Phonological awareness refers to the ability to understand and manipulate the phonemes in spoken words. This meta-analysis explores the impact of phonological awareness training on children’s word-identification and reading skills.

Research Questions

  1. Does training students in phonological awareness substantially affect the learning-to-read process?
  2. Is phonological training more effective when the program combines phonological training with written letters or words?
  3. Does starting early with phonological training more effective than starting later in childhood?
  4. Do children with reading problems profit more from a phonological awareness training than children who develop in a normal way?

Research Design

  • Number of Studies Included | 70
  • Number of Subjects | Over 5,843. In some instances, groups of children were analyzed instead of each individual child.
  • Years Spanned | 1973-1997

Research Subjects
Children participating in phonological awareness instruction.

Age/Grade of Subjects
Age/Grade Range = preschool through elementary school.

Specified Disability
Learning Disabilities (LD), or other unspecified special education categories.

Participants received a variety of types of phonological awareness training. In some studies, Phonological training was delivered in the context of letter training, reading, or writing instruction; while in others phonetics was taught as a separate lesson. Phonological awareness (including phoneme segmentation, phoneme blending, and sound deletion) was the observed outcome measure.

Duration of Intervention
Not reported


  1. The effect of phonemic training on phonological awareness skills was remarkably strong.
  2. The effect on reading was only moderate.

Combined Effects Size

  1. Effect of phonemic training on phonological awareness = 1.04 (large).
  2. Effect of phonological awareness training on reading skills = 0.44 (moderate).

Phonological training is highly effective for improving children’s phonemic awareness skills. Phonological awareness training has weaker, yet still significant, effects on overall reading ability, spelling, and reading comprehension. Phonological awareness is a predictor of reading; however, it is not necessarily the strongest predictor of reading. It should be provided as one component of a complete early reading program, not as the entire program. Phonological awareness training appears to be most successful when it is combined with letter training. In other words, children benefit more from being exposed to print and being taught that there is a connection between spoken sounds and written letters than from simply playing spoken phonemic awareness games.


* Meta-Analysis | A widely-used research method in which (1) a systematic and reproducible search strategy is used to find as many studies as possible that address a given topic; (2) clear criterion are presented for inclusion/exclusion of individual studies into a larger analysis; and (3) results of included studies are statistically combined to determine an overall effect (effect size) of one variable on another.

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