Thursday, June 9, 2011

Developing Early Literacy Skills: A Meta-Analysis of Alphabet Learning and Instruction (2010)

Shayne B. Piasta, Richard K. Wagner (2010) Reading Research Quarterly, 45(1), 8–38. DOI:10.1598/RRQ.45.1.2


Developing alphabet knowledge has become a primary objective of preschool instruction and intervention, but there's little agreement on how to foster alphabet knowledge effectively. This study is a meta-analysis of the effects of instruction on alphabet learning outcomes.

Results -
Instructional impact differed by type of alphabet outcome and content of instruction.
School-based instruction: larger effects than home-based instruction;
small-group instruction: larger effects than individual tutoring
Evidence of transfer of alphabet instruction to early phonological, reading, spelling skills.

Research demonstrates a reciprocal relationship between letter names and corresponding sounds. It suggests that instruction in letter names may improve letter-sound learning, especially for letters with names that include their sounds. (e.g., Evans, Bell, Shaw, Moretti, & Page, 2006; Levin, Shatil-Carmon, & Asif-Rave, 2006; McBride-Chang, 1999; Share, 2004; Treiman, Tincoff, Rodriguez, Mouzaki, & Francis, 1998; Treiman, Weatherston, & Berch, 1994).

Phoneme instruction also enhances alphabet learning (reciprocal relationship). Considerable evidence: (Burgess & Lonigan, 1998; Lonigan, Burgess, & Anthony, 2000; McBride-Chang, 1999; Wagner et al., 1994; Ball & Blachman, 1991).

Meta-analysis features:
Current study improves on National Early Literacy Panel (NELP) meta-analysis that failed to examine the reciprocal relationship between letters/sounds instruction. It includes all studies providing alphabet training and alphabet outcomes through 2006. It examines effects for 5 alphabet outcomes: letter name knowledge, letter sound knowledge, letter name fluency, letter sound fluency, and letter writing.  It targets alphabet instruction--letter names training, letter sounds, or both. It also differentiates between studies with multiple components and alphabet-only instruction.

Examined studies for:
- Effects of alphabet training within literacy instruction curriculum
- Effects of phonological training on alphabet knowledge
- Causal relations between alphabet instruction and emergent literacy skill from studies in which only children’s alphabet knowledge was manipulated.


Characteristics of reviewed studies
  • Sixty-three total with 8,468 participants, 4,466 receiving treatment of alphabet instruction.
  • Eighty-two independent effect sizes (k)
  • Fifty-three studies had multiple instructional components
    • Alphabet instruction and phonological training studies (n = 44, k = 59). 
    • Oral language studies (k = 9)
    • Writing/printing studies (k = 11)
    • Concepts of print studies (k = 7) 
    • Word identification studies (decoding, k = 12; sight words, k = 12)
    • Book use studies (k = 11)
  • Ten studies of  alphabet only
    • three letter names only (k = 3)
    • four letter sounds only (k = 4)
    • three both letter names and sounds (k = 5) 
  • Total instructional time range 120 to 5,793 minutes (M = 1250.46 minutes, SD = 1335.69)
Impact of Multicomponential Instruction on Alphabet Outcomes:
  • Significant effect on all alphabet outcomes except letter name fluency with overall effect sizes of 0.65 for letter sound knowledge to 0.43 for letter name knowledge.
  • Letter name outcomes affected when letter name or both letter/sound instruction combined
  • Instruction targeting letter/sound knowledge improved letter/sound outcomes with and without PA training
  • Letter name instruction had significant impact on letter sound knowledge
  • Letter sound fluency reliably affected by letter sound plus phonological instruction.
Impact of Pure Alphabet Instruction on Alphabet and Early Literacy Outcomes
  • Positive effects of pure alphabet instruction on alphabet outcomes but most effect sizes not reliable. 
  • Exception: letter sound knowledge study, with significant overall effect; also showed significant impact on letter name instruction (based on only a single effect size, McMahon, Rose, & Parks, 2003)
  • Phonological outcomes not effected by alphabet instruction when measured after intervention
  • Exception: significant positive impact of letter name instruction found in McMahon et al., 2003 study
  • Only 4 with follow up assessment resulting in no significant effects on PA, reading, or spelling
Discussion Quotes
". . .the present study demonstrates a significant impact of instruction on children’s alphabet
learning. Effect size magnitude depended not only on the type of alphabet knowledge assessed, but also instructional factors such as skills taught, setting, grouping, and duration" (p. 20).

"Letter name knowledge, letter sound knowledge, and letter writing outcomes showed effects ranging from 0.14 to 0.65 across the various domains of alphabet knowledge when considering both multicomponential and pure alphabet instruction" (p. 20).

"Effects for fluency outcomes were less clear. For multicomponential studies, letter naming fluency was the only outcome to show no effect of instruction, yet a moderate (though also nonsignificant) effect was found when letter names constituted the sole focus of instruction . . .multicomponential studies showed a reliable moderate effect on letter sound fluency outcomes that was not apparent when considering the study providing only letter sound training." (p. 20).

"...parents and teachers alike tend to impart letter knowledge to young children, particularly focusing on letter names (Ellefson, Treiman, & Kessler, 2009). Children in control conditions may thus learn letter names to a similar extent as children receiving additional instruction" (p. 22).

"Teachers and classroom instruction proved just as effective as the more controlled instruction provided by researchers in clinics and laboratories" (p. 23).

"Results were generally inconclusive with respect to the causal relations between alphabet learning and development of other early literacy skills. Small effects on reading skills were found when assessed immediately following instruction, but effects were no longer apparent 2 to 12 months later" (p. 24).

". . . positive and negative effects were found when using quasi-experimental designs, in the
presence of selection biases, with teacher- and researcher implemented instruction, and for samples including older and younger, at-risk and non–at-risk children" (p. 24).

". . . additional research on how to effectively impart alphabet knowledge remains necessary" (p. 24).