Figure 7From: Item response analysis of the Positive and Negative Syndrome Scale Option characteristic curves for Item 19: Mannerisms and posturing. Option characteristic curves describing the probability with ratings of 3 or less are made as a function of symptom severity for items recommended to define symptom remission in patients. Results show that the option characteristic curves for this item will be endorsed at a much more severe level of symptomatology than other items and is therefore redundant or should be revised. The broken line (---) shows the option characteristic curves for a revised Item 19, where remission is defined on the basis of a score less than or equal to 2 (rather than 3).Back to article page