Derrington 2012 thesis.pdf - Anglia Ruskin Research Online

more varied (Centre= -2.5; CVC=16.33). In total, 67% teachers reported
improvement and that students were coping better at school after they had had music
therapy.
6.6.2 The teachers’ questionnaire: inferential statistics
The analysis of variants (ANOVA) was carried out on teacher 1 scores, to observe
any statistical significance, or p-values. Levene’s test (1960) assessed the quality of
variances and tested the null hypothesis that the error variance of the dependent
variable was equal across groups, shown in table 6.6c.i (appendix 6.6c) 48 .
The test of between-subjects effects presented in table 6.6c.II (appendix 6.6c) shows
that the baseline scores, made by teacher 1, were not a significant influence on the
change in scores (p-value=0.205). Likewise, neither of the other main effects of
school or group, nor their interaction, made a significant difference to the change in
scores (p-values =0.900, 0.368 and 0.712, respectively).
The observed power for the main effects of the teacher’s baseline assessment, the
school and the group was just 24%, 6% and 14% respectively. This proves that the
sample size was not large enough to reject the null hypothesis: the null hypothesis
was that there was no effect of these variables on the change scores. Therefore this
does not mean that there was no influence of the main effects but there was not
enough data to show it. As a result, no further analysis using the other teachers’
scores was carried out.
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%) !Levene’s test looked at all the possible variants and combinations between the
groups and schools. The result proved that the standard deviation was not significant
(p-value= 0.482) because it was similar enough between both groups, and therefore
the null hypothesis need not be rejected. This is important because the assumptions
for the ANOVA were that the data were normally distributed and of equal variances.
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