Table 4.
Form Length |
Cronbach’s alpha (95% CI) | Correlation of summed scores (95% CI) |
Correlation of factor scores (95% CI) |
---|---|---|---|
Item 9 Eligible for Inclusion in Short Forms | |||
1 | NA | 0.527 (0.511, 0.543) | NA |
2 | 0.533 (0.504, 0.563) | 0.804 (0.796, 0.811) | 0.800 (0.792, 0.808) |
3 | 0.727 (0.712, 0.741) | 0.863 (0.857, 0.868) | 0.869 (0.863, 0.874) |
4 | 0.801 (0.790, 0.810) | 0.892 (0.887, 0.896) | 0.895 (0.890, 0.899) |
5 | 0.809 (0.799, 0.819) | 0.920 (0.916, 0.923) | 0.912 (0.909, 0.916) |
6 | 0.835 (0.826, 0.843) | 0.939 (0.937, 0.942) | 0.931 (0.928, 0.934) |
7 | 0.846 (0.839, 0.854) | 0.971 (0.970, 0.973) | 0.980 (0.979, 0.980) |
8 | 0.858 (0.851, 0.865) | 0.986 (0.986, 0.987) | 0.989 (0.989, 0.990) |
9 | 0.866 (0.860, 0.873) | 1.000 (1.000, 1.000) | 1.000 (1.000, 1.000) |
Item 9 Ineligible for Inclusion in Short Forms | |||
1 | NA | 0.781 (0.772, 0.79) | NA |
2 | 0.779 (0.763, 0.794) | 0.849 (0.842, 0.855) | 0.860 (0.855, 0.866) |
3 | 0.816 (0.806, 0.826) | 0.887 (0.882, 0.892) | 0.891 (0.886, 0.895) |
4 | 0.805 (0.795, 0.814) | 0.919 (0.916, 0.923) | 0.910 (0.907, 0.914) |
5 | 0.832 (0.824, 0.840) | 0.940 (0.936, 0.941) | 0.930 (0.927, 0.933) |
6 | 0.845 (0.838, 0.852) | 0.970 (0.969, 0.971) | 0.978 (0.977, 0.979) |
7 | 0.857 (0.850, 0.863) | 0.984 (0.984, 0.985) | 0.988 (0.987, 0.988) |
8 | 0.866 (0.860, 0.872) | 0.997 (0.997, 0.997) | 0.998 (0.998, 0.998) |
Bold values represent those of the final selected form.