Table 6.
Rasch Analysis of Computer Adaptive Testing item sets
| Analysis | Item Sets and samples | Chi- Squarea | Df | P | Residual Item |
Residual Person |
PSI Reliability |
% tests >5% | 95%LCI | N |
|---|---|---|---|---|---|---|---|---|---|---|
| SD | SD | |||||||||
| 1 | Core Set- CAT15 Sample 1 | 153.0 | 135 | 0.138 | 1.586 | 0.967 | 0.87 | 6.8 | 4.7 | 500 |
| 2 | Core Set- CAT15 Sample 2 | 172.5 | 135 | 0.016 | 1.711 | 0.934 | 0.88 | 6.6 | 4.5 | 500 |
| 3 | Core Set- CAT15 Sample 3 | 165.2 | 135 | 0.040 | 1.576 | 0.880 | 0.88 | 5.1 | 3.0 | 500 |
| 4 | Second Set- CAT10 Sample 1 | 106.6 | 90 | 0.112 | 1.314 | 0.927 | 0.84 | 5.6 | 3.2 | 500 |
| 5 | Second Set- CAT10 Sample 2 | 114.2 | 90 | 0.043 | 1.694 | 0.993 | 0.85 | 3.6 | 1.1 | 500 |
| 6 | Second Set- CAT10 Sample 3 | 106.6 | 90 | 0.112 | 1.498 | 1.021 | 0.86 | 5.2 | 3.0 | 500 |
| Ideal Values | >0.05a | <1.4 | <1.4 | >0.70 | <5.0 | <5.0 |
aBonferroni Adjusted (0.008 for 6 tests)