The vocabulary weakness of children with SCD is best characterized as a developmental delay rather than a developmental deficit¶

Claim · All claims
Evidence · 1 study (2 entries) · associational r3 · q3
Currency · newest study 2019 · not yet checked against its sources · not reviewed by a person

Subclaims¶

q3 i? Under regression-based matching, the grouping variable did not explain meaningfully unique vocabulary variance over and above reading comprehension, supporting the delay hypothesis. → Spencer 2019 q3 i? For the more stringent SCD-540 group, the grouping variable was statistically significant but explained essentially no variance, so the delay conclusion held. → Spencer 2019 (2)

Evidence¶

Spencer 2019¶

Spencer, M., Wagner, R. K., & Petscher, Y. (2019). The Reading Comprehension and Vocabulary Knowledge of Children with Poor Reading Comprehension despite Adequate Decoding: Evidence from a Regression-Based Matching Approach. Journal of Educational Psychology. https://doi.org/10.1037/edu0000274

q3 · i? · associational · r3

Regression-based matching analysis (multilevel models) for the SCD-2540 subsample in the Results section. Controlling for SAT-10, the group effect was non-significant (0.11, p = .543), so vocabulary "was best characterized as developmentally delayed."

"The addition of the grouping variable suggested that weak PPVT differences were observed between groups when controlling for SAT-10 (0.11, p = .543; Table 4). Thus, children’s vocabulary weakness was best characterized as developmentally delayed."

Spencer 2019 (2)¶

Spencer, M., Wagner, R. K., & Petscher, Y. (2019). The Reading Comprehension and Vocabulary Knowledge of Children with Poor Reading Comprehension despite Adequate Decoding: Evidence from a Regression-Based Matching Approach. Journal of Educational Psychology. https://doi.org/10.1037/edu0000274

q3 · i? · associational · r3

Same regression-based matching analysis for the stringent SCD-540 subsample. The significant group effect (6.01, p < .001) explained about 0–1% of variance at student and district levels; the authors attribute the significance to the large sample size.

"the grouping variable suggested that significant differences in PPVT scores were observed when controlling for SAT-10 (6.01, p < .001); however, the inclusion of this grouping variable did not translate into and understanding of individual differences explained according to the random effect reduction in variances"

Discussion¶

Related Claims¶

• The pattern of SCD weaknesses is consistent across identification criteria, but criteria identify widely differing proportions of children — related
• Children with specific reading comprehension difficulties show substantially poorer reading comprehension than vocabulary relative to typical readers — related
• Most children with SCD have vocabulary weaknesses, with intact vocabulary being rare — related
• Study findings support multiplicative over additive versions of the Simple View for children with SCD — related
• Expressive vocabulary uniquely explains variance in reading comprehension of adult struggling readers — related