QUALIFICATION
Comparisons were made between selected groups based on qualification, for results obtained to Section B (Teaching), Section B (Research), Section C (needs and expectations) and Section D (retention strategies). For this purpose, analysis of variance (ANOVA) was used because there were more than two groups to compare. The groups selected based on qualification were:
a) Doctorate b) Masters
c) Honours or BTech and degree
If, based on the ANOVA, differences were found between the groups (with an F test p-value < 0.05), additional post-hoc tests had to be conducted to determine for each between group difference, the statistical significance of these differences. In cases like these, the following tests were used to measure significance:
a) For statistical significance, the Scheffé test was used and significance indicated at p-value < 0.05;
b) For practical significance, Cohen's d > 0.20 was used to indicate practical significance
Cohen’s d is used to measure effect size, implying the strength of a specific phenomenon. The higher the Cohen d, the greater the effect size number of observations (n’s) (Gravetter & Wallnau, 2009, p. 264).
Table 5.37 illustrates the interpretation levels for Cohen’s d for measuring the effect of qualification on results, based on sample size (N) and number of observations (n’s).
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Table 5.37: Interpretation intervals for Cohen's d
<0.20 Not significant 0.20 - 0.49 Small significance 0.50 - 0.79 Medium significance 0.80+ Large significance
Anova results for differences in responses to Section B 5.5.1
(Teaching) based on qualification
Table 5.38 shows the descriptive statistics for Section B (Teaching) based on qualification.
Table 5.38: Descriptive statistics for B (Teaching) by qualification
Group All Doctorate Masters Hons or BTech or degree
n 136 57 48 31
Mean 3.09 3.37 2.97 2.74
SD 0.86 0.90 0.75 0.79
95% CI low 2.94 3.13 2.76 2.45
95% CI high 3.23 3.61 3.19 3.03
For Section B (Teaching) a higher aggregate mean score was obtained for respondents with a doctorate (mean 3.37) than for those with a master’s degree (mean 2.97) or honours, BTech or degree (2.74). On face value and logic one would conclude that those with a doctorate therefore had more teaching experience than those with a master’s degree, who again had more teaching experience than those with an honours or BTech or degree.
However, to determine whether this was statistically correct, an ANOVA had to be conducted.
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Table 5.39 presents the ANOVA results for Section B (Teaching) based on qualification.
Table 5.39: ANOVA – Results for B (Teaching) by qualification
Source of variation SS df MS F p-value
Between groups 8.976 2 4.488 6.563 .002
Within groups 90.946 133 0.684
Total 99.922 135
Table 5.39 shows that the F test p-value was < 0.05, which implied that differences were found in the responses based on qualification. To determine the significance of these results, a post-hoc test, namely the Scheffé test and Cohen’s d were conducted. The results for the Scheffé test and Cohen’s d are presented in Table 5.40.
Table 5.40: Sheffé test and Cohen’s d for ANOVA results by qualification
Qualification 1 Qualification 2 Diff. M1-M2 Scheffé p Cohen's d
Doctorate Masters 0.40 .053 n or a
Doctorate Hons or BTech or degree 0.63 .004 0.73 Medium Masters Hons or BTech or degree 0.24 .466 n or a
The results show that the differences in responses to Section B (Teaching) were significant for those with a doctorate and those with an honours, BTech or degree (Scheffé .004) and that this difference was of practical significance (Cohen’s d 0.73). The results merely suggest moderate significant differences between these two groups in terms of teaching experience. No significant differences were found in the teaching experience of those with a doctorate and master’s degree, or those with a master’s degree and honours, BTech or degree. The results suggest that those with honours, BTech and degrees were less experienced in teaching and that teaching developmental interventions should be aimed at this group and not on those with doctorates or masters’ degrees.
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ANOVA results for differences in responses to Section B 5.5.2
(Research) based on qualification
Table 5.41 indicates the descriptive statistics for results for Section B (Research) based on qualification.
Table 5.41: Descriptive statistics for B (Research) by qualification
Group All Doctorate Masters Hons. or BTech or Degree
n 136 57 48 31
Mean 2.69 3.66 2.18 1.70
SD 1.22 0.91 0.90 0.87
95% CI low 2.48 3.42 1.92 1.39
95% CI high 2.90 3.90 2.44 2.02
For Section B (Research), a higher aggregate mean score was obtained for respondents with a doctorate (mean 3.66) than for those with a master’s degree (mean 2.18) or honours, BTech or degree (1.70). On face value and logic one would conclude that those with a doctorate therefore had more research experience than those with a master’s degree, who again had more research experience than those with an honours, BTech or degree. However, to determine whether this was statistically correct, an ANOVA was conducted.
Table 5.42 presents the ANOVA results for Section B (Research) based on qualification.
Table 5.42: ANOVA – B (Research) by Qualification
Source of variation SS df MS F p-value Between groups 96.077 2 48.039 60.051 <.005
Within groups 106.396 133 0.800
Total 202.473 135
Table 5.42 shows that the F test p-value was < 0.05, which implied that differences were found in the responses based on qualification. To determine the significance of these results, the Scheffé test and Cohen’s d were
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conducted. The results for the Scheffé test and Cohen’s d are presented in Table 5.43.
Table 5.43: Descriptive and inferential statistics for ANOVA – B (Research) by qualification
Qualification 1 Qualification 2 Diff. M1-M2 Scheffé p Cohen's d
Doctorate Masters 1.48 <.0005 1.64 Large
Doctorate Hons or BTech or degree 1.95 <.0005 2.19 Large
Masters Hons or BTech or degree 0.47 .074 n/a
The results show that the differences in responses to Section B (Research) were significant between those with a doctorate and those with a master’s degree (Scheffé .0005) and that this difference was of large practical significance (Cohen’s d 1.64). The results also show significant differences in the responses between those with a doctorate and those with an honours, BTech or degree (Scheffé .0005) and that this difference was of large practical significance (Cohen’s d 2.19). The results suggest that those with a doctorate had significant more research experience than those without a doctorate.
ANOVA results for differences in responses to Section C (needs 5.5.3
and expectations) and Section D (retention strategies) based on qualification
The results for both Sections C and D were also analysed based on qualification. No differences were found in the responses to the total factors in these sections based on qualification. As illustration, the descriptive statistics for Section C (total factors) are presented.
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Table 5.44: Descriptive statistics for Section C (total factors) by Qualification
Group All Doctorate Masters Hons. or BTech or Degree
n 136 57 48 31
Mean 4.20 4.16 4.24 4.20
SD 0.53 0.54 0.51 0.55
95% CI low 4.11 4.01 4.09 4.00
95% CI high 4.29 4.30 4.39 4.40
It is evident that the mean scores for Section C based on qualification are similar for those with a doctorate (4.26), master’s degree (4.24) and honours, BTech or degree (4.20).
Table 5.45 shows the ANOVA results for the responses to Section C (total factors). Total based on qualification.
Table 5.45: ANOVA – Section C (total factors) by Qualification
Source of variation SS df MS F p-value Between groups 0.197 2 0.098 0.348 .707
Within groups 37.567 133 0.282
Total 37.764 135
The results reveal that respondents with doctorates, masters’ degrees and an honours, BTech or degree did not have different needs and expectations (Section C).
Because similar results were found for Section D (total factors) based on qualification, it can also be concluded that there were not different perceptions of the retention strategies offered by NMMU (Section D) based on qualification.
165 CONCLUSION
5.6
In this chapter the statistical analysis and interpretation of the results of the empirical study were presented and discussed. The quantitative and qualitative research findings were summarised and reflected upon in a comprehensive manner.
In Chapter Six the conclusions and recommendations based on the findings of the empirical study are presented and discussed.
166 CHAPTER 6