DClinPsy Portfolio Volume 1 of 3 - University of Hertfordshire ...

Eating Disorder Risk Category Inflexibility
Low
N
Mean (Std error)
Median
SD
Min-Max
Skewness (Std error)
Moderate
N
Mean (Std error)
Median
SD
Min- Max
Skewness (Std error)
High
N
Mean (Std error)
Median
SD
Min-Max
Skewness (Std error)
68
26.43 (1.34)
27.50
11.01
0-46
-0.10 (0.29)
17
33.82 (2.37)
33
9.76
15-56
0.44 (0.55)
11
35.27 (5.21)
42
17.29
11-62
-0.07 (0.66)
As can be seen from Table 8 above the high EDR group has the highest mean inflexibility
score (35.27) followed by the moderate EDR group (33.82) and then the low group mean
was 26.43. This suggests that the higher the EDR the higher the degree of inflexibility,
this would be tested using inferential statistics. In view of the group sizes it was decided
to use non parametric analysis to prevent producing results that would violate parametric
assumptions. Therefore the above hypothesis was explored using the Mann Whitney U
Test.
Table 9 – Results of the Mann Whitney U Test exploring mean difference between EDR
groups in relation to inflexibility
Comparison of Inflexibility Mean difference (SE)
1. Low EDR compared to
Moderate EDR
2. Low EDR compared to High
EDR
Z p value (1tailed)
Effect size
(Cohen’s d)
-7.40 -2.29 0.01 0.71
-8.85 -1.67 0.05 0.61
170