In this kind of study, there is inevitable attrition, since nine and ten year olds had left by the time of the third test. Moreover, all would have had many musical experiences before entering the school that might predispose them to music.
6.4.2 Choir School
In the choir school, 40 of the original 71 children had moved up into year 8 - the secondary section of the same school. The numbers are shown in Table 6.2.
Age of children in 2001
Wavel (2001)
Wave 2 (2003)
10yrs 71 40
Table 6.2 Age of children in Choir School 3 in 2001
6.4.3 Independent School results
The analysis strategy in the non-specialist independent school was to take advantage of the Bentley norms, in order to group members of cohorts into those whose 2002 scores were higher than might be expected on the basis of their age and those whose scores were as expected or lower than expected for their age. This was a principled way of lowering the number of groups for comparison. It also allowed for the possibility that the starting level of those children playing a musical instrument might be higher by age 7 than the level of other children.
Even though the 1966 Bentley test norms were very old, this method of dividing into cohorts was more meaningful than simple reliance on chronological age. It also retained numbers in comparison groups, as can be seen from Table 6.3.
Grouping according to Bentley norms in
2002 Wavel Wave 2 Wave 3
Above expected (AB) 83 53 20
At or below expected (CDE) 46 26 24
Total 129 79 44
Table 6.3 Grouping children for waves o f testing in the Independent non-specialist school
Table 6.4 then further divides the children into four categories for each wave of testing, on the basis of whether they played an instrument or not, and whether their Bentley scores were higher than expected for their age in 2002 or not.
Bentley norm in 2002 Wave 1 Wave 2 Wave 3
Learning to play Number Number Number
Above expected No 29 16 9
(AB) Yes 54 37 11
As expected or below No 21 12 14
(CDE) Yes 25 14 10
Table 6.4 Numbers tested at each w ave o f testing according to starting level Bentley norms and w hether they learned an instrument or not in the Independent non-specialist school
Although children were expected to gravitate towards musical experience on the basis of already established interests, those in the Independent School were encouraged to leam an instrument. However, encouragement did not seem to offset a tendency for those higher on Bentley norms to be more likely to take up an instrument. The first column in Table 6.4 shows that just over two thirds (54 out of 83) in the AB
category were learning to play an instrument in 2002, while a half (25 out of 46) in the CDE category were learning an instrument.
An indication of change based on Bentley norms was to compare their status in 2002 with what would be expected for their age group in 2004.
The rate or likelihood of moving from one category to another by the third wave of testing is shown in Table 6.5.
Pupils Learning an
Table 6.5 Rates of changing status according to Bentley Norms as a function of learning to play an instrument in the Independent non
specialist school
A Fisher’s Exact test analysis was carried out to examine the significance of change in category between the first and last time of testing, both for children learning and instrument and those not. This showed the importance of learning an instrument affecting change. If not learning an instrument, less than half (38%) had moved category between the first and last time of testing from the expected level or below to above.
However 17% had gone to the expected level or lower for the age group.
The significance of change could readily have occurred by chance,
p=.768. For those playing an instrument, only two out of 81 had receded, while two thirds (66.1%) of those starting below the A/B level had higher Bentley test scores by the third time of testing. This tendency was highly significant, with p=.014 on the Fisher exact test.
A less crude analysis can be conducted using the children’s scores on the Bentley test but still using the division according to the scoring category at the first time of testing. Table 6.6 shows the mean scores of pupils on the Bentley test in the categories of Table 6.5 (above and below expectations in relation to the norms, and according to whether or not Yes 37.32 5.16 25 39.07 7.55 14 43.10 5.32 10
As
expected or below
No 28.38 5.97 29 30.75 10.79 16 38.89 6.09 9 Yes 28.61 6.22 54 34.43 7.87 37 38.36 7.51 11
Table 6.6 Bentley test scores, by whether an instrument was being learned for those at or below and higher than original Bentley norms in the Independent non-specialist school
The results in Table 6.6 show a simple time effect, with each group of pupils ending up with a higher score than at the first time of testing.
Authors such as Singer and W illett (2003) insisted that provided that all
children’s scores are kept for use in analysis, significance of effects of change over time can be tested. Peugh and Enders (2005) explain how to perform the recommended calculations with well-known statistical packages. The same methods apply to this analysis where, instead of keeping four groups for comparison according to chronological age, they were divided according to their Bentley norm categories (Bentley categories A and B and categories C, D or E)
Figure 6.1 is a graph showing what happened over time at the three