Item | Difficulty parameter of category 0 vs 1–6 | 0–1 vs 2–6 | 0–2 vs 3–6 | 0–3 vs 4–6 | 0–4 vs 5–6 | 0–5 vs 6 | Discrimination parameter |
---|---|---|---|---|---|---|---|
1 | − 2.782 | − 1.710 | − 0.462 | 1.745 | 3.491 | 4.995 | 0.901 |
2 | − 2.372 | − 1.804 | − 0.702 | 0.096 | 1.454 | 2.673 | 1.314 |
3 | − 2.335 | − 1.490 | − 0.468 | 0.420 | 1.591 | 2.794 | 1.160 |
4 | − 1.098 | − 0.214 | 0.660 | 1.411 | 2.395 | 3.141 | 1.582 |
5 | 0.015 | 0.449 | 0.808 | 1.467 | 2.003 | 2.283 | 3.622a |
6 | − 0.758 | − 0.034 | 0.589 | 1.160 | 1.936 | 2.922 | 1.884 |
7 | − 0.155 | 0.330 | 0.753 | 1.356 | 2.042 | 2.415 | 3.539a |
8 | − 1.085 | − 0.373 | 0.315 | 1.267 | 2.135 | 3.012 | 2.083 |
9 | − 0.427 | 0.048 | 0.481 | 1.043 | 1.831 | 2.244 | 3.452a |
10 | − 0.969 | − 0.294 | 0.210 | 1.091 | 1.870 | 2.564 | 1.855 |
11 | − 0.941 | − 0.305 | 0.184 | 0.781 | 1.487 | 2.191 | 1.994 |
12 | 0.075 | 0.575 | 0.990 | 1.774 | 2.253 | 2.647 | 2.466 |
13 | − 0.965 | − 0.352 | 0.192 | 0.997 | 1.670 | 2.614 | 2.314 |
14 | − 0.663 | − 0.118 | 0.342 | 1.107 | 1.859 | 2.515 | 2.810 |
Mean | − 1.033 | − 0.378 | 0.278 | 1.123 | 2.001 | 2.786 | 2.213 |