Figure 4

Option characteristic curves and expected item total score for Item 5: Grandiosity. Option characteristic curves (solid lines) and expected item total score (dashed line) are plotted as a function of scores on the Positive Symptomatology Subscale form the PANNS, expressed as standard normal scores (lower x-axis) and expected total scores (upper x-axis). Option characteristic curves (solid lines) indicate that a number of opportunities for improvement. Options 2, 3 and 4 overlap substantially as do Options 6 and 7 suggesting rating these options is inherently difficult for raters. Option 1 in this item was most frequently endorsed by over half the sample, indicating that these options are only endorsed as a higher level of symptoms severity than in other options. The item characteristic curve (broken line) increases smoothly in all but the lowest region of symptom severity, but increases more slowly than the item characteristic curve in Item 1 or 3. Expected item scores for this item are generally lower at comparable regions of symptom severity than for Items 1 or 3.