Online Materials 1: CBM-W Accuracy Raw Scores
Table 1. Raw score means and SD for CBM-W accuracy variables SC Mean (SD)
MS Mean (SD)
WLC Mean (SD) CBM-W Proportion Words Spelled Correctly t1 0.85 (0.11) 0.82 (0.13) 0.86 (0.07) t2 0.90 (0.09) 0.85 (0.11) 0.88 (0.08) t3 0.89 (0.10) 0.86 (0.12) 0.06 (0.11) CBM-W Proportion Correct Word Sequences t1 0.83 (0.09) 0.05 (0.11) 0.89 (0.07) t2 0.87 (0.09) 0.84 (0.14) 0.88 (0.08) t3 0.90 (0.08) 0.89 (0.08) 0.89 (0.08) CBM-W Lexical Diversity (TTR) t1 0.74 (0.09) 0.72 (0.11) 0.75 (0.08) t2 0.68 (0.08) 0.70 (0.09) 0.69 (0.08) t3 0.71 (0.09) 0.72 (0.10) 0.66 (0.10) CBM-W Total Words Written t1 49.62 (18.73) 45.46 (19.95) 45.00 (12.05)
t2 53.52 (19.21) 50.42 (17.50) 49.76 (16.93) t3 53.87 (25.56) 51.42 (20.97) 58.68 (20.26)
CBM-W Complete Sentences t1 0.86 (1.35) 0.73 (1.31) 1.00 (1.24)
t2 1.48 (1.24) 1.58 (1.79) 1.71 (1.65) t3 1.65 (1.67) 1.33 (1.46) 1.27 (1.32) CBM-W Words in Complete Sentences t1 14.48 (23.94) 11.50 (20.37) 13.61 (15.96)
t2 25.22 (20.18) 21.69 (23.37) 26.38 (22.99) t3 27.91 (25.62) 27.21 (24.66) 22.55 (26.91)
Note: SC=Sentence Combining Intervention, MS=Morphological Spelling Intervention, WLC=Waiting List Control
Online Materials 2: CBM-W Fluency ANOVA
To explore the responsiveness to the intervention of the SWs on the CBM-W fluency variables (total words written, complete sentences, and words in complete sentences). A series of mixed-measures ANCOVAs, with performance at t1 as a covariate, was conducted. As explained in the paper all these results showed no significant main effect of intervention group or time, with no significant group by time interactions. For all these variables, the covariate of t1 performance had a statistically
significant effect on subsequent performance. The details of these ANCOVAs is presented below.
The mixed measures ANCOVA for Total Words Written on the CBM-W task revealed no statistically significant main effect of no statistically significant main effect of intervention group (F(2,58)=0.68, p=.513), time (F(1,58)=0.08, p=.781), and no statistically significant intervention group by time interaction (F(2,58)=2.16, p=.125). The covariate of t1 performance had a statistically significant effect on subsequent performance (F (1, 58)=35.09, p=.023, η2ρ =.02).
The mixed measures ANCOVA for Complete Sentences on the CBM-W task revealed no statistically significant main effect of intervention group (F(2,58)=0.07, p=.936) or time (F(1,58)=2.93, p=.093)
and no statistically significant intervention group by time interaction (F(2,58)=1.44, p=.245). The covariate of t1 Complete Sentences was statistically significant (F(1,58)=12.14, p=.001, η2ρ =.17).
The mixed measures ANCOVA for Words in Complete Sentences on the CBM-W task revealed no statistically significant main effect of intervention group (F(2,58)=0.08, p=.925) or time (F(1,58)=0.56, p=.458) and no statistically significant intervention group by time interaction (F(2,58)=1.11, p=.338).
The covariate of t1 Words in Complete Sentences was statistically significant (F(1,58)=15.10, p<.001, η2ρ =.21).
Table 2. Raw score means, SD and effect sizes for the CBM-W fluency variables Sentence
Combining Intervention
Morphological Spelling Intervention
Waiting List Control
Effect Sizes (Hedge’s g)
N Mean (SD) N Mean (SD) N Mean (SD) SC-MS SC-WLC MS-WLC
Total Words Written t2 21 55.71 (17.60) 24 50.83 (18.15) 17 50.71 (17.48) 0.27 0.28 0.01
t3 21 55.38 (26.26) 24 51.42 (20.97) 17 60.88 (20.84) 0.17 -0.22 -0.44
Complete Sentences t2 21 1.52 (1.25) 24 1.63 (1.84) 17 1.94 (1.59) -0.07 -0.29 -0.17
t3 21 1.76 (1.70) 24 1.33 (1.46) 17 1.42 (1.42) 0.26 0.21 0.14
Words in Complete Sentences t2 21 26.00 (20.29) 24 22.33 (23.90) 17 30.76 (22.54) 0.16 -0.22 -0.35
t3 21 28.95 (26.08) 24 27.21 (24.65) 17 24.88 (29.58) 0.07 0.14 0.08
Total Punctuation t2 21 2.95 (2.22) 24 3.13 (2.56) 17 3.71 (2.57) -0.07 -0.31 -0.22
t3 21 3.52 (3.66) 24 2.71 (2.29) 17 2.65 (2.18) 0.26 0.28 0.03
