Vocabulary development was broadly similar for students with and without a learning disability, while reading comprehension gains decelerated for both groups yet the LD group started over a standard deviation lower¶

Claim · All claims
Evidence · 1 study (2 entries) · associational r2–r3 · q2
Currency · newest study 2020 · not yet checked against its sources · not reviewed by a person

Subclaims¶

q2 i? Students with and without an LD started with similar vocabulary levels and showed similarly shaped vocabulary growth, though non-LD students made somewhat larger average vocabulary gains from kindergarten to third grade. → Quinn 2020 q2 i? Reading comprehension gains decelerated over time for both groups, and LD students had higher estimated reading comprehension change scores between all three grade intervals despite their much lower starting point. → Quinn 2020 (2)

Evidence¶

Quinn 2020¶

Quinn, Jamie M.; Wagner, Richard K.; Petscher, Yaacov; Roberts, Greg; Menzel, Andrew J.; Schatschneider, Christopher. (2020). Differential Co-Development of Vocabulary Knowledge and Reading Comprehension for Students with and without Learning Disabilities. Journal of Educational Psychology. https://doi.org/10.1037/edu0000382

q2 · i? · associational · r2

Split violin plots of model-estimated growth and score distributions for a randomly selected subset of 200 students (100 per group), with PPVT vocabulary measured annually from kindergarten. Vocabulary distributions "largely overlap at each time point," consistent with the printed intercept means of −0.91 versus −1.07.

"For vocabulary knowledge (Figure 1, top), students with or without an LD started with similar levels of vocabulary. The average growth lines split somewhat over time, but the distributions of vocabulary scores largely overlap at each time point."

Quinn 2020 (2)¶

Quinn, Jamie M.; Wagner, Richard K.; Petscher, Yaacov; Roberts, Greg; Menzel, Andrew J.; Schatschneider, Christopher. (2020). Differential Co-Development of Vocabulary Knowledge and Reading Comprehension for Students with and without Learning Disabilities. Journal of Educational Psychology. https://doi.org/10.1037/edu0000382

q2 · i? · associational · r3

Model-estimated average change scores computed from the LCS change score equations for average students. Non-LD change scores fell from 1.02 (grades 1–2) to 0.32 (grades 3–4); LD change scores (1.11, 0.70, 0.38) were higher at each interval, but the LD group "start over one standard deviation below the mean of reading comprehension" and do not catch up.

"Reading comprehension gains decelerated quickly over time from a one standard deviation increase between first grade and second grade to about one third of a standard deviation increase between third grade and fourth grade."

Discussion¶

Learner Variables¶

• Learning Disabilities and Developmental Differences — predictor: learners who differ on it differ in outcomes

Related Claims¶

• For typically developing students, vocabulary knowledge and reading comprehension show bidirectional leading influences over time in kindergarten through fourth grade — related
• Students with a learning disability started about one standard deviation lower in reading comprehension and did not catch up to typically developing peers by fourth grade, which the authors interpret as a developmental deficit — related
• Under the fitted model, non-LD students who start with high vocabulary but low reading comprehension are expected to grow nearly twice as much in reading comprehension as LD students starting at the same point — related
• For students with a school-identified learning disability, there were no significant direct cross-lagged pathways between vocabulary knowledge and reading comprehension — related
• Students with disabilities benefited similarly from PACT but remained about 1 standard deviation behind nondisabled peers at posttest — related