The graded response model (GRM), which is based on item response theory (IRT), was used to evaluate the psychometric properties of the inattention and hyperactivity/impulsivity symptoms in an ADHD rating scale. To accomplish this, parents and teachers completed the DSM-IV ADHD Rating Scale (DARS; Gomez et al., Journal of Child Psychology and Psychiatry, 40, 265-274, 1999) for a group of 1,475 primary school-aged children. The results for the discrimination parameters showed that all symptoms for both groups of respondents were generally good for discriminating their respective latent traits. For virtually all symptoms, their threshold values showed moderate to large increases in the level of the latent trait at each subsequent response dichotomy, with the symptoms being especially good at representing the appropriate traits from mean to moderately high trait levels. The item information function values for most symptoms indicated reasonable reliability from, approximately, the mean trait levels to moderately high trait levels. These findings indicate good psychometric properties for the parent and teacher ratings of the DARS. The implications of the findings for the use of the DARS and other similar scales are discussed. © 2008 Springer Science+Business Media, LLC.

Item Type:	Refereed Article
Research Division:	Psychology and Cognitive Sciences
Research Group:	Psychology
Research Field:	Health, Clinical and Counselling Psychology
Objective Division:	Health
Objective Group:	Public Health (excl. Specific Population Health)
Objective Field:	Mental Health
Author:	Gomez, R (Professor Rapson Gomez)
ID Code:	55054
Year Published:	2008
Web of Science® Times Cited:	26
Deposited By:	Psychology
Deposited On:	2009-03-04
Last Modified:	2015-01-27
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