Such findings are consistent with research on other externalizing behavior problems [e.g., attention-deficit/hyperactivity disorder (ADHD); Frazier et al., 2007; Marcus and Barry, 2011], indicating that dimensional models demonstrate stronger validity coefficients with criterion measures than dichotomous models. Other studies (e.g., Fergusson and Horwood, 1995) also have found that dimensional measures of externalizing behavior, defined more broadly, are better predictors of subsequent problems than are categories of diagnoses and that associated features, and outcomes appear to relate to such behaviors in a linear fashion. Despite the compelling nature of such studies and the support they render for a dimensional approach to assessing ODD, they, nevertheless, do not directly address the issue of the latent structure of ODD. For example, ODD may have a categorical latent structure even if there are varying levels of severity within the taxon. Such a latent structure would not be inconsistent with the research to date finding that a dimensional treatment of ODD better predicts outcomes. To more directly address the issue of its underlying structure, taxometric analyses, which allow an examination of the latent structure of a theoretical construct via a set of indicators for that construct, can be used (Meehl, 1995; Waller and Meehl, 1998).
