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The WWC review of interventions for early childhood education addresses children's outcomes in six domains: oral language, print knowledge, phonological processing, early reading/writing, cognition, and math. 10
Oral language. Five studies examined outcomes in the domain of oral language: three studies showed statistically significant and positive effects and two studies showed indeterminate effects.
Lonigan et al. (1999) found a statistically significant difference favoring children in the Dialogic Reading intervention group on one of the four outcome measures (verbal expression subscale of the Illinois Test of Psycholinguistic Ability; ITPA-VE), and this effect was confirmed to be statistically significant by the WWC. The authors found no statistically significant differences between the intervention and comparison groups on the other three measures. In this study the effect was statistically significant and positive, according to WWC criteria.
Lonigan and Whitehurst (1998) analyzed group differences for the combined intervention groups (Dialogic Reading at school, Dialogic Reading both at school and at home, and Dialogic Reading at home) and the comparison group. Because WWC ECE does not review interventions implemented in the home, the WWC calculated group differences on the three outcome measures for the combined Dialogic Reading at school and both at school and at home intervention group versus the comparison group and did not find statistically significant differences on any measure in analyses using data combined for centers with high and low implementation. In this study the effect was indeterminate, according to WWC criteria.
Lonigan and Whitehurst (1998) also analyzed group differences for the combined intervention groups within high and low compliance centers. The WWC calculated group differences on the three outcome measures for the combined Dialogic Reading at school and both at school and at home intervention group versus the comparison group separately for high and low compliance centers. For the high compliance centers, the WWC did not find statistically significant differences on any measure; however, the effect was large enough to be called substantively important and positive, according to WWC criteria. For the low compliance centers, the WWC did not find statistically significant differences on any measure and the effect was indeterminate, according to WWC criteria. These analyses suggest that level of implementation of Dialogic Reading has an impact on child outcomes in the oral language domain.
In addition, Lonigan and Whitehurst (1998) reported group differences separately for the Dialogic Reading at school group and the Dialogic Reading both at school and at home group within the high and low compliance centers. For the Dialogic Reading at school group in the high compliance centers, the WWC did not find any statistically significant differences between this group and the comparison group on any of the outcome measures. However, the effect was large enough to be called substantively important and positive, according to WWC criteria. For the Dialogic Reading both at school and at home group in the high compliance centers, the authors reported two statistically significant and positive differences favoring the Dialogic Reading group and the statistical significance of these effects was confirmed by the WWC. The effect was statistically significant and positive, according to WWC criteria. For the Dialogic Reading at school group in the low compliance centers, the authors reported a statistically significant and negative finding and the statistical significance of this effect was confirmed by the WWC. The effect was statistically significant and negative, according to WWC criteria. For the Dialogic Reading both at school and home group in the low compliance centers, the WWC found no statistically significant differences between the intervention and comparison groups, either positive or negative. However, the effect was large enough to be called substantively important and positive, according to WWC criteria.
Wasik and Bond (2001) found statistically significant differences favoring the Dialogic Reading children on two measures of oral language, and the WWC confirmed this statistical significance. 11 In this study the effect was statistically significant and positive, according to WWC criteria.
Whitehurst, Arnold, et al. (1994) found statistically significant differences favoring children in the combined intervention groups (Dialogic Reading at school and Dialogic Reading both at school and at home) on two of the four measures in this domain (EOWPVT-R and Our Word), but only the statistical significance for EOWPVT-R was confirmed by the WWC. The authors found no statistically significant differences on the other two measures. 12 In this study the effect was statistically significant and positive, according to WWC criteria.
Whitehurst, Arnold, et al. (1994) also analyzed group differences separately for the Dialogic Reading at school group and the Dialogic Reading both at school and at home group. For the Dialogic Reading at school group, the WWC did not find statistically significant differences between the intervention and comparison groups on any outcome measure and the effect was indeterminate, according to WWC criteria. For the Dialogic Reading both at school and home group, the WWC did not find statistically significant differences between the intervention and comparison groups. However, the effect was large enough to be called substantively important and positive, according to WWC criteria.
Crain-Thoreson and Dale (1999) analyzed findings for six measures in this outcome domain. The findings favored the intervention group for five of the measures and favored the comparison group for the sixth measure. None of these effects, however, were statistically significant; and the average effect was neither statistically significant nor large enough to be considered substantively important. In this study the effect was indeterminate, according to WWC criteria.
Phonological processing. Lonigan et al. (1999) found no statistically significant effects for any of the four outcome measures and the average effect across the four measures was not large enough to be considered substantively important. In this study the effect was indeterminate, according to WWC criteria.
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,10 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).
|Institute of Education Sciences
