In my study, the pairs of standard deviations which were sufficiently different to warrant the use of the more complicated formula occurred in single-letter recognition of 2.26 and 1.46); and cluster and digraph recognition (2.97 and 2.74). The (s.d’s smaller post-test standard deviations of the other three categories fell within 5% of the larger value. However, to be consistent, all effect sizes were calculated using the more complex formula. 4.4.3 Analyses of variance one [or more] groups of participants are studied at different time points ... a “Where and two-way mixed analysis of variance will be particularly appropriate” (Howitt Cramer, 2008: 196 & 197). This variant of anova (also known in older texts as analysis of variance with repeated measures on one was used here. factor’) Appendices 21-25 contain the anova results produced by SPSS from the RCT data. The anova results of interest were not those for the main factor, time, but for the interaction of time and group membership this was to investigate whether or not – one of the two groups made significantly more progress than the other. 4.4.4 t-tests of post-test differences These were used to investigate whether the two mean scores differed groups’ significantly at the post-test stage (appendices 21-25). Here, because there was a hypothesis identifying the likely direction of difference (in favour of the intervention group), one-tailed were identified and presented. p-values 4.4.5 Confidence intervals around effect sizes
In my study, the pairs of standard deviations which were sufficiently different to warrant the use of the more complicated formula occurred in single-letter recognition (s.d’s of 2.26 and 1.46); and cluster and digraph recognition (2.97 and 2.74). The smaller post-test standard deviations of the other three categories fell within 5% of the larger value. However, to be consistent, all effect sizes were calculated using the more complex formula. 4.4.3 Analyses of variance “Where one [or more] groups of participants are studied at different time points ... a two-way mixed analysis of variance will be particularly appropriate” (Howitt and Cramer, 2008: 196 & 197). This variant of anova (also known in older texts as analysis of variance with repeated measures on one factor’) was used here. Appendices 21-25 contain the anova results produced by SPSS from the RCT data. The anova results of interest were not those for the main factor, time, but for the interaction of time and group membership – this was to investigate whether or not one of the two groups made significantly more progress than the other. 4.4.4 t-tests of post-test differences These were used to investigate whether the two groups’ mean scores differed significantly at the post-test stage (appendices 21-25). Here, because there was a hypothesis identifying the likely direction of difference (in favour of the intervention group), one-tailed p-values were identified and presented. 4.4.5 Confidence intervals around effect sizes
AAA_EdD_-_THE_WHOLE_THING_%28post_viva%29.docx