EIR® showed large alphabetics effect sizes and improvement indices of +29 to +42 percentile points in the one qualifying study¶

Claim · All claims
Evidence · 1 study (2 entries) · causal r2 · q3 · i3 large
Currency · newest study 2008 · not yet checked against its sources · not reviewed by a person

Subclaims¶

Reading the evidence codes

q is the design tier, i the impact, n the sample, and the kind with its r the rigour judged within that kind: what each code means.

This claim: no standardized effect is recorded in observations/ for it yet, so no benchmark reading is possible.

q3 i? The average improvement index for alphabetics was +36 percentile points, ranging from +29 to +42 across findings. → Early Intervention in Reading® 2008 q3 i3 The vowel sounds effect size was 1.39, statistically significant, with an improvement index of +42. → Early Intervention in Reading® 2008 (2)

Evidence¶

Early Intervention in Reading® 2008¶

Early Intervention in Reading®. (2008). WWC Intervention Report, What Works Clearinghouse, U.S. Department of Education. http://www.earlyinterventioninreading.com

q3 · i? · causal · r?

WWC calculations for the Taylor et al. (1991) randomized controlled trial report that the "average improvement index for alphabetics is +36 percentile points" with a range of +29 to +42; the improvement index is based only on effect size, regardless of significance or design.

"The average improvement index for alphabetics is +36 percentile points for the one study, with a range of +29 to +42 percentile points across findings."

Early Intervention in Reading® 2008 (2)¶

Early Intervention in Reading®. (2008). WWC Intervention Report, What Works Clearinghouse, U.S. Department of Education. http://www.earlyinterventioninreading.com

q3 · i3 · causal · r2

WWC calculations for the Taylor et al. (1991) randomized controlled trial (Appendix A3.1) report a vowel-sounds mean difference of 4.18 favoring EIR®, an "effect size" of 1.39, statistically significant, with an improvement index of +42.

"Vowel sounds Grade 1 12/56 10.62 (3.18) 6.44 (2.72) 4.18 1.39 Statistically significant +42"

Discussion¶

EIR® produced statistically significant positive effects on first-grade alphabetics outcomes (segmentation and blending, vowel sounds) — a broader claim this one bears on
The evidence base for EIR® is small: only one of seven reviewed studies met WWC evidence standards — related

Page metadata

Field	Value
`type`	`claim`
`id`	`eir-alphabetics-effect-sizes-improvement-index`
`title`	`EIR® showed large alphabetics effect sizes and improvement indices of +29 to +42 percentile points in the one qualifying study`
`description`	`EIR® showed large alphabetics effect sizes and improvement indices of +29 to +42 percentile points in the one qualifying study`
`status`	`review`
`evidence_strength`	`moderate`
`newest_evidence`	`2008`
`generated`	by `process:wiki-ingest` on `2026-10-07`
`trust`	unverified — no one has confirmed this page's content
`sources`	2 — `early-intervention-in-reading-2008`, `early-intervention-in-reading-2008-2`

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