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Effectiveness
Findings
The WWC review of interventions for beginning reading addresses student outcomes in four domains: alphabetics, reading fluency, comprehension, and general reading achievement. 10 The studies included in this report cover three domains: alphabetics, fluency, and comprehension. Within alphabetics, results for four constructs are reported: phonemic awareness, phonological awareness, phonics, and letter knowledge. The findings below present the authors' estimates and WWC-calculated estimates of the size and the statistical significance of the effects of Ladders to Literacy on students. 11
Alphabetics. Four studies reviewed findings in the alphabetics domain. O'Connor (1999, Study A: Intensive Professional Development) found no statistically significant difference between the Ladders to Literacy group and comparison group performance on the phonemic awareness outcome (Test of Short-Term Memory), while the WWC found a statistically significant positive effect. 12 The study author found and the WWC confirmed statistically significant positive effects on two phonological awareness measures (Segmentation and Blending) and one standardized measure of phonics (Woodcock-Johnson (WJ) Letter-Word Identification subtest). The author did not report statistically significant results for Rhyme production. For the Letter Knowledge measure of Rapid Letter Naming, the author found a statistically significant effect; in WWC calculations, the effect was not statistically significant. The average effect size across the six outcomes was statistically significant.
O'Connor (1999, Study B: Traditional Professional Development) found no statistically significant difference between the Ladders to Literacy group and comparison group performance on the phonemic awareness outcome (Test of Short-Term Memory). The author reported statistically significant effects of Ladders to Literacy across the phonological skills outcomes (Segmentation, Rhyme Production, and Blending) and measure of phonics (WJ Word Identification). The WWC confirmed statistically significant effects only for the segmentation measure. The average effect size across the six outcomes was statistically significant.
O'Connor et al. (1996) reported statistically significant effects of Ladders to Literacy across all measures (Sound Repetition, Blending, First Sound, Segmenting, Rhyme Production, Rapid Letter Naming, and the WJ Word Identification subtest). The WWC confirmed statistically significant effects only for the segmenting measure. The average effect size across the seven outcomes was not statistically significant but was large enough to be considered substantively important (an effect size greater than 0.25) according to WWC criteria.
Fuchs et al. (2001) found positive and statistically significant effects of Ladders to Literacy on two phonological awareness measures (Segmentation and Blending); WWC confirmed the effect for the blending task, while the effect for segmentation was not statistically significant. 13 The authors found no statistically significant difference between the Ladders to Literacy group and comparison group performance on three phonics measures—Rapid Letter Sound and two subtests of the Woodcock Reading Mastery Test: Word Attack and Word Identification. The average effect size across the three outcomes was not statistically significant.
Fluency. O'Connor et al. (1996) found a positive, but not statistically significant effect of Ladders to Literacy on the fluency outcome (Test of Oral Reading Fluency).
Comprehension. Three studies examined the effects of Ladders to Literacy in the vocabulary construct (O'Connor, 1999, Study A: Intensive Professional Development; O'Connor, 1999, Study B: Traditional Professional Development; and O'Connor et al., 1996). The studies' authors did not find a statistically significant effect of Ladders to Literacy on the Peabody Picture Vocabulary Test for any study.
Rating of effectiveness
The WWC rates the effects of an intervention in a given outcome domain as: positive, potentially positive, mixed, no discernible effects, potentially negative, or negative. The rating of effectiveness takes into account four factors: the quality of the research design, the statistical significance of the findings, the size of the difference between participants in the intervention and the comparison conditions, and the consistency in findings across studies (see the WWC Intervention Rating Scheme).
11 The level of statistical significance was reported by the study authors or, where necessary, calculated by the WWC to correct for clustering within classrooms or schools and for multiple comparisons. For an explanation, see the WWC Tutorial on Mismatch. See the WWC Intervention Rating Scheme for the formulas the WWC used to calculate the statistical significance. In the case of Ladders to Literacy, corrections for clustering and multiple comparisons were needed for all three O'Connor studies and corrections for multiple comparisons were needed for Fuchs et al. (2001).
12 The author reported results for the total sample and at-risk children, and the WWC focused only on typical learners.
13 The size of the effect was not reported here because student-level data were not available to the WWC. Please see A3.1 for a more detailed explanation.
