Robin van Rijthoven

126 Chapter 5 Finally, it is important to mention that when we added phonological awareness, rapid automatized naming, verbal working memory or semantic abilities separately in Step 2, combined with a corresponding interaction term with group in Step 3, the effects of Trial 5 and Verbal consolidation did not change and remained non-significant. Predicting response to intervention by verbal learning and consolidation To answer the second part of the research question, regarding the impact of verbal learning and consolidation on the response to a phonics through spelling intervention, we again conducted six hierarchical regression analyses. The same procedure was followed as in predicting reading and spelling outcomes, but with different outcome measures (i.e., change per session for word decoding, pseudoword decoding, and spelling). The descriptive statistics of these outcome measures are presented in Table 5.5. In the analyses, pretest was included as a control variable. The results (see Table 5.6 and 5.7) showed an effect of pretest on spelling, but no significant effects of verbal learning or consolidation on each of the outcome measures: Verbal learning and consolidation were not significantly linked to progress made in a phonics through spelling intervention. Table 5.5 Descriptive Statistics of Outcome Measures (Raw and Percentile) including Pre- and Posttest Scores as well as Change Scores and Change per Session. Raw scores Percentile scores M SD M SD Word decoding Pretest 31.37 13.23 5.51 5.61 Posttest 41.04 14.74 9.70 11.20 Change scores 10.29 6.35 4.16 9.18 Change per session 0.38 0.23 0.15 0.34 Pseudoword decoding Pretest 20.61 10.05 8.39 8.09 Posttest 29.36 12.28 12.63 11.74 Change scores 9.59 9.05 4.36 8.92 Change per session 0.38 0.34 0.18 0.34 Spelling Pretest 49.96 28.30 7.74 14.50 Posttest 75.20 27.47 22.00 20.54 Change scores 27.39 11.44 8.71 17.36 Change per session 1.02 0.43 0.30 0.62 Note. The change scores are calculated by subtracting pre- from posttest scores. The change per session was calculated by deviding the change scores by the number of sessions the intervention lasted.