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Ask A REL Response

November 2020


What research has been conducted on which letter-sound correspondences/patterns must be taught and which can be learned implicitly?


Following an established REL Southeast research protocol, we conducted a search for research reports as well as descriptive study articles on which letter-sound correspondences/patterns must be taught and which can be learned implicitly We focused on identifying resources that specifically addressed which letter-sound correspondences/patterns must be taught and which can be learned implicitly The sources included ERIC and other federally funded databases and organizations, research institutions, academic research databases, and general Internet search engines (For details, please see the methods section at the end of this memo.)

We have not evaluated the quality of references and the resources provided in this response. We offer them only for your reference. These references are listed in alphabetical order, not necessarily in order of relevance. Also, we searched the references in the response from the most commonly used resources of research, but they are not comprehensive and other relevant references and resources may exist.

Research References

  1. Bowers, J. S. (2020). Reconsidering the evidence that systematic phonics is more effective than alternative methods of reading instruction. Educational Psychology Review, 32(3) 681–705.
    From the abstract: "There is a widespread consensus in the research community that reading instruction in English should first focus on teaching letter (grapheme) to sound (phoneme) correspondences rather than adopt meaning-based reading approaches such as whole language instruction. That is, initial reading instruction should emphasize systematic phonics. In this systematic review, I show that this conclusion is not justified based on (a) an exhaustive review of 12 meta-analyses that have assessed the efficacy of systematic phonics and (b) summarizing the outcomes of teaching systematic phonics in all state schools in England since 2007. The failure to obtain evidence in support of systematic phonics should not be taken as an argument in support of whole language and related methods, but rather, it highlights the need to explore alternative approaches to reading instruction."
  2. Chen, V., & Savage, R. S. (2014). Evidence for a simplicity principle: Teaching common complex grapheme-to-phonemes improves reading and motivation in at-risk readers. Journal of Research in Reading, 37(2), 196–214.
    From the abstract: "This study examines the effects of teaching common complex grapheme-to-phoneme correspondences (GPCs) on reading and reading motivation for at-risk readers using a randomised control trial design with taught intervention and control conditions. One reading programme taught children complex GPCs ordered by their frequency of occurrence in children's texts (a "simplicity principle"). The other reading programme taught children word usage. Thirty-eight students participated in the 9-week programme of 30 supplemental small group sessions. Participants in the complex GPC group performed significantly better at post-tests with generally large value-added effect sizes (Cohen's d) at both by-participant and by-item for spelling, d?=?1.85, d?=?1.16; word recognition with words containing taught GPCs, d?=?0.96, d?=?0.95; word recognition, d?=?0.79, d?=?0.61, and reading motivation, d?=?0.34, d?=?0.56. These findings suggest that the simplicity principle aids in structuring maximally effective supplemental phonic interventions."
  3. Christensen, C. A., & Bowey, J. A. (2005). The efficacy of orthographic rime, grapheme-phoneme correspondence, and implicit phonics approaches to teaching decoding skills. Scientific Studies of Reading, 9(4), 327–349.
    From the abstract: "This study compared the efficacy of two decoding skill-based programs, one based on explicit orthographic rime and one on grapheme--phoneme correspondences, to a control group exposed to an implicit phonics program. Children in both explicit decoding programs performed consistently better than the control group in the accuracy with which they read and spelled words covered in the program. Only children in the grapheme--phoneme correspondence program consistently spelled transfer words better than children in the control group. In addition, children in the grapheme-phoneme correspondence group consistently read words more quickly than children in the control group. Children in both explicit decoding programs scored higher than the children in the control group on measures of reading comprehension and oral reading at posttest."
  4. Earle, G. A., & Sayeski, K. L. (2017). Systematic instruction in phoneme-grapheme correspondence for students with reading disabilities. Intervention in School and Clinic, 52(5), 262–269.
    From the abstract: "Letter-sound knowledge is a strong predictor of a student's ability to decode words. Approximately 50% of English words can be decoded by following a sound-symbol correspondence rule alone and an additional 36% are spelled with only one error. Many students with reading disabilities or who struggle to learn to read have difficulty with phonology, an understanding of how sounds are organized within language. This can result in difficulty grasping the alphabetic principle, the knowledge of the relation between speech sounds and the letters/letter patterns that represent them. Research has demonstrated the benefits of intensive, explicit instruction for developing struggling readers' capacity to identify phonemes and apply knowledge of phoneme-grapheme correspondence for decoding. In this article, common misconceptions and basic tenets of effective letter-sound instruction are provided to help special educators and reading interventionists plan for effective phoneme-grapheme correspondence instruction for students with reading disabilities or who are at risk for reading failure."
  5. Piasta, S. B., & Wagner, R. K. (2010). Learning letter names and sounds: Effects of instruction, letter type, and phonological processing skill. Journal of Experimental Child Psychology, 105(4), 324–344.
    From the abstract: "Preschool-age children (N = 58) were randomly assigned to receive instruction in letter names and sounds, letter sounds only, or numbers (control). Multilevel modeling was used to examine letter name and sound learning as a function of instructional condition and characteristics of both letters and children. Specifically, learning was examined in light of letter name structure, whether letter names included cues to their respective sounds, and children's phonological processing skills. Consistent with past research, children receiving letter name and sound instruction were most likely to learn the sounds of letters whose names included cues to their sounds regardless of phonological processing skills. Only children with higher phonological skills showed a similar effect in the control condition. Practical implications are discussed. (Contains 3 tables and 1 figure.)"
  6. Sunde, K., Furnes, B., Lundetrae, K. (2020). Does introducing the letters faster boost the development of children's letter knowledge, word reading and spelling in the first year of school? Scientific Studies of Reading, 24(2), 141–158.
    From the abstract: "Learning the relationships between letters and sounds is a key component of early literacy development and a central aim during the first year of school. Introducing one new letter a week is the most common approach in many countries, but little is known about how the pace of letter instruction contributes to the development of early literacy skills. This study used a natural experiment to investigate how a faster pace of letter instruction influences the development of letter knowledge, word reading, and spelling during the first year of school. Regression analysis showed that a faster pace yielded significantly better results for all outcome measures, and logistic-regression models showed that the lowest-performing children benefited more than the highest-performing one from a faster pace. The study concludes with a discussion of those novel findings and suggestions about their implications for teaching practice."


Keywords and Search Strings
The following keywords and search strings were used to search the reference databases and other sources:

  • Phoneme-grapheme correspondence, instructional strategies
  • Explicit instruction of letter-sound correspondences
  • Explicit or implicit instruction, letter-sound correspondence
  • Phoneme-grapheme correspondence, instructional strategies
  • Phoneme-grapheme mapping, explicit or implicit, teaching methods

Databases and Resources
We searched ERIC for relevant resources. ERIC is a free online library of over 1.6 million citations of education research sponsored by the Institute of Education Sciences. Additionally, we searched Google Scholar and PsychInfo.

Reference Search and Selection Criteria

When we were searching and reviewing resources, we considered the following criteria:

  • Date of the publication: References and resources published for last 15 years, from 2003 to present, were include in the search and review.
  • Search Priorities of Reference Sources: Search priority is given to study reports, briefs, and other documents that are published and/or reviewed by IES and other federal or federally funded organizations, academic databases, including ERIC, EBSCO databases, JSTOR database, PsychInfo, PsychArticle, and Google Scholar.
  • Methodology: Following methodological priorities/considerations were given in the review and selection of the references: (a) study types - randomized control trials,, quasi experiments, surveys, descriptive data analyses, literature reviews, policy briefs, etc., generally in this order (b) target population, samples (representativeness of the target population, sample size, volunteered or randomly selected, etc.), study duration, etc. (c) limitations, generalizability of the findings and conclusions, etc.

This memorandum is one in a series of quick-turnaround responses to specific questions posed by educational stakeholders in the Southeast Region (Alabama, Florida, Georgia, Mississippi, North Carolina, and South Carolina), which is served by the Regional Educational Laboratory Southeast at Florida State University. This memorandum was prepared by REL Southeast under a contract with the U.S. Department of Education's Institute of Education Sciences (IES), Contract ED-IES-17-C-0011, administered by Florida State University. Its content does not necessarily reflect the views or policies of IES or the U.S. Department of Education nor does mention of trade names, commercial products, or organizations imply endorsement by the U.S. Government.