Introduction
When today 's educators discuss the ingredients of effective programs to teach children to read, phonemic awareness (PA) receives much attention. However, not everyone is convinced. In education, particularly in the teaching of reading over the years, the choice of instructional methods has been heavily influenced by many factors ,not only teachers' own frontline experiences about what works, but also politics, economics, and the popular wisdom of the day. The pendulum has swung back and forth between holistic, meaning-centered approaches and phonics approaches without much hope of resolving disagreements. Meanwhile, substantial scientific evidence has accumulated purporting to shed light on reading acquisition processes and effective instructional approaches (Anderson et al., 1985; Adams, 1990; Snow, 1998). Many studies investigating the effectiveness of phonemic awareness instruction have contributed to this body of evidence. Proponents believe that this research holds promise of placing reading instruction on a more solid footing and ending the periodic upheavals and overhauls of reading instructional practices.
The purpose of this report of the National Reading Panel (NRP) was to examine the scientific evidence relevant to the impact of phonemic awareness instruction on reading and spelling development. In the analyses conducted, the NRP sought answers to questions such as the following: Is phonemic awareness instruction effective in helping children learn to read? Under what circumstances and for which children is it most effective? Were studies showing its effectiveness designed appropriately to yield scientifically valid findings? What does a careful analysis of the findings reveal? How applicable are these findings to classroom practice? To evaluate the adequacy and strength of the evidence, the NRP conducted a meta-analysis. The literature was searched to locate all experimental studies that included a PA treatment and a control group and that measured reading as an outcome of the treatment.
There were several reasons why phonemic awareness instruction was selected for review and analysis. Correlational studies have identified phonemic awareness and letter knowledge as the two best school-entry predictors of how well children will learn to read during their first 2 years in school. This evidence suggests the potential instructional importance of teaching PA to children. Many experimental studies have evaluated the effectiveness of PA instruction in facilitating reading acquisition. Results are claimed to be positive and to provide a scientific basis documenting the efficacy of PA instruction. There is currently much interest in PA programs among teachers, principals, and publishers. State adoption committees have prescribed the inclusion of PA training in reading instruction materials approved for use in schools. It is thus important to determine whether PA instruction lives up to these claims and, if so, to identify circumstances that govern its effectiveness.
