Table 6 Graded item parameters for the Performance + Squinting testlets and Satisfaction + Squinting testlets
NVPTQ Domain/Item Parameter | Book | Newspaper | Menu | Nutrition Label |
|---|---|---|---|---|
Performance + Squinting | ||||
a | 6.40 | 13.04 | 5.24 | 3.86 |
b1 | − 0.34 | − 0.33 | − 0.69 | − 0.43 |
b2 | 0.09 | 0.08 | − 0.17 | 0.32 |
b3 | 0.52 | 0.51 | 0.27 | 0.90 |
b4 | 1.02 | 0.98 | 0.90 | 1.36 |
b5 | 1.83 | 1.63 | 1.49 | 1.90 |
Satisfaction + Squinting | ||||
a | 10.12 | 10.24 | 6.66 | 4.70 |
b1 | − 0.24 | − 0.33 | − 0.49 | − 0.14 |
b2 | 0.09 | 0.12 | − 0.04 | 0.30 |
b3 | 0.39 | 0.41 | 0.23 | 0.79 |
b4 | 1.36 | 1.30 | 1.38 | 1.76 |