Introducing Phonics to Learners Who Struggle: Content and Embedded Cognitive Elements
Vadasy, Patricia F.; Sanders, Elizabeth A. (2021). Reading and Writing: An Interdisciplinary Journal, v34 n8 p2059-2080 Oct 2021. Retrieved from: https://eric.ed.gov/?id=EJ1306388
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examining68Students, gradeK
Single Study Review
Review Details
Reviewed: May 2026
- Single Study Review (findings for Explicit phonics instruction with flexible-thinking activities–Vadasy & Sanders (2021))
- Randomized Controlled Trial
- Meets WWC standards without reservations because it is a randomized controlled trial with low attrition.
This review may not reflect the full body of research evidence for this intervention.
Evidence Tier rating based solely on this study. This intervention may achieve a higher tier when combined with the full body of evidence.
Findings
|
Outcome measure |
Comparison | Period | Sample |
Intervention mean |
Comparison mean |
Significant? |
Improvement index |
|---|---|---|---|---|---|---|---|
|
Color card sort |
Explicit phonics instruction with flexible-thinking activities–Vadasy & Sanders (2021) vs. Explicit phonics instruction without flexible-thinking activities–Vadasy & Sanders (2021) |
0 Days |
Full sample;
|
17.00 |
20.00 |
No |
-- |
|
Outcome measure |
Comparison | Period | Sample |
Intervention mean |
Comparison mean |
Significant? |
Improvement index |
||
|---|---|---|---|---|---|---|---|---|---|
| Show Supplemental Findings | |||||||||
|
Letter names |
Explicit phonics instruction with flexible-thinking activities–Vadasy & Sanders (2021) vs. Explicit phonics instruction without flexible-thinking activities–Vadasy & Sanders (2021) |
0 Days |
Full sample;
|
63.00 |
65.00 |
No |
-- | ||
|
Letter sound writing |
Explicit phonics instruction with flexible-thinking activities–Vadasy & Sanders (2021) vs. Explicit phonics instruction without flexible-thinking activities–Vadasy & Sanders (2021) |
0 Days |
Full sample;
|
63.00 |
68.00 |
No |
-- | ||
|
Letter sounds |
Explicit phonics instruction with flexible-thinking activities–Vadasy & Sanders (2021) vs. Explicit phonics instruction without flexible-thinking activities–Vadasy & Sanders (2021) |
0 Days |
Full sample;
|
68.00 |
77.00 |
No |
-- | ||
|
Consonant-vowel-consonant word spelling |
Explicit phonics instruction with flexible-thinking activities–Vadasy & Sanders (2021) vs. Explicit phonics instruction without flexible-thinking activities–Vadasy & Sanders (2021) |
0 Days |
Full sample;
|
9.00 |
19.00 |
No |
-- | ||
|
Outcome measure |
Comparison | Period | Sample |
Intervention mean |
Comparison mean |
Significant? |
Improvement index |
||
|---|---|---|---|---|---|---|---|---|---|
| Show Supplemental Findings | |||||||||
|
Consonant-vowel-consonant word reading |
Explicit phonics instruction with flexible-thinking activities–Vadasy & Sanders (2021) vs. Explicit phonics instruction without flexible-thinking activities–Vadasy & Sanders (2021) |
0 Days |
Full sample;
|
11.00 |
20.00 |
No |
-- | ||
Evidence Tier rating based solely on this study. This intervention may achieve a higher tier when combined with the full body of evidence.
Sample Characteristics
Characteristics of study sample as reported by study author.
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18% English language learners -
Female: 47%
Male: 53% -
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West
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Race Other or unknown 100% -
Ethnicity Other or unknown 100% -
Eligible for Free and Reduced Price Lunch Other or unknown 100%
Study Details
Setting
The study was conducted in a kindergarten-only school in the Pacific Northwest. Students came from 22 kindergarten classrooms in the school.
Study sample
The study included kindergarten students who had very limited alphabet knowledge at the beginning of the study. The school identified students who knew no more than two letter names or sounds, and teachers then confirmed which students were eligible. Researchers randomly assigned 36 students to receive explicit phonics instruction with flexible-thinking activities and 37 students to receive explicit phonics instruction without flexible-thinking activities. The study reported that five students were not included in the findings because they moved or were frequently absent. The findings were based on 68 students, including 33 students who received explicit phonics instruction with flexible-thinking activities and 35 students who received explicit phonics instruction without flexible-thinking activities.
Intervention Group
Explicit phonics instruction with flexible-thinking activities was designed to help kindergarten students learn letter-sound connections and beginning word-reading skills. This version of explicit phonics instruction also included short activities intended to help students shift attention between different features of letters and words. Students received one-on-one instruction from trained research assistant instructors for 20 minutes per session over 6 weeks. Lessons taught 13 letter-sound connections, including single-letter sounds and common two-letter sounds. Students practiced letter sounds, blending sounds to read words, spelling, sorting words, reading words in sentences, and finding sounds in words. In some activities, students practiced switching between saying letter names and letter sounds, finding letters in different word positions, or sorting words by different features.
Comparison Group
Students in the comparison group received explicit phonics instruction without flexible-thinking activities. This instruction covered the same 13 letter-sound connections as the intervention condition and was delivered one-on-one by trained research assistant instructors for 20 minutes per session over 6 weeks. The lessons focused on helping students accurately connect printed letters with sounds and apply those sounds to early reading and spelling tasks. Students practiced activities such as saying and writing letter sounds, blending sounds to read words, spelling words with letter tiles, sorting words by first sound, and reading words in short sentences.
Support for implementation
The research assistant instructors had previous training and classroom experience, including experience as classroom teachers or paraeducators. Before instruction began, the instructors studied the lessons, attended an all-day training, practiced delivering lessons, and received feedback from the researchers. During the study, research staff were on site daily, met with instructors informally, provided individual coaching, and sent weekly emails with instructional tips. Researchers also observed instruction and documented whether instructors delivered the lesson content as intended.
An indicator of the effect of the intervention, the improvement index can be interpreted as the expected change in percentile rank for an average comparison group student if that student had received the intervention.
For more, please see the WWC Glossary entry for improvement index.
An outcome is the knowledge, skills, and attitudes that are attained as a result of an activity. An outcome measures is an instrument, device, or method that provides data on the outcome.
A finding that is included in the effectiveness rating. Excluded findings may include subgroups and subscales.
The sample on which the analysis was conducted.
The group to which the intervention group is compared, which may include a different intervention, business as usual, or no services.
The timing of the post-intervention outcome measure.
The number of students included in the analysis.
The mean score of students in the intervention group.
The mean score of students in the comparison group.
The WWC considers a finding to be statistically significant if the likelihood that the finding is due to chance alone, rather than a real difference, is less than five percent.
The WWC reviews studies for WWC products, Department of Education grant competitions, and IES performance measures.
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Study findings for this report.
Based on the direction, magnitude, statistical significance, and sample size of the findings within a domain, the WWC assigns effectiveness ratings as one of the following: Tier 1 (strong evidence), Tier 2 (moderate evidence), Tier 3 (promising evidence), uncertain effects, and negative effects. For more detail, please see the WWC Handbook.
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Tier 2 Moderate indicates moderate evidence of effectiveness, and
Tier 3 Promising indicates promising evidence of effectiveness,
as defined in the
non-regulatory guidance for ESSA
and the regulations for ED discretionary grants (EDGAR Part 77).