Table 2 BAQ items sorted into 5 classes showing their psychometric properties
From: How important is distractor efficiency for grading Best Answer Questions?
Classes | Mean DIFi (SD) and range | Mean DISi (SD) range | n and (% of items) | Mean FDs/item (SD) and range |
|---|---|---|---|---|
A (excellent) | 0.53 (0.05) 0.43–0.59 | 0.47 (0.07) 0.4–0.59 | 9 (2.57) | 2.44 (0.53) 2–3 |
B (good) | 0.58 (0.14) 0.31–0.79 | 0.3 (0.1) 0.15–0.64 | 122 (34.86) | 2.3 (0.91) 1–4 |
C (fair) | 0.6 (0.31) 0.08–0.93 | 0.23 (0.07) 0.15–0.50 | 61 (17.43) | 2.07 (1.14) 0–4 |
D (remediable) | 0.68 (0.29) 0.04–0.99 | 0.08 (0.04) 0.01–0.14 | 90 (25.71) | 1.42 (1.19) 0–4 |
E (discarded) | 0.61 (0.33) 0–1 | -0.02 (0.05) -0.20–0 | 68 (19.43) | 1.45 (1.17) 0–4 |
|  | TOTAL | 350 (100) | 654/350 = 1.87 | |