The issue of categorical versus dimensional models of psychopathology has for years been one of great controversy within the mental health field. Answering the question of whether or not various forms of psychopathology are dimensional versus categorical (taxonic) may have numerous implications for better understanding the etiology of these conditions as well as for assessment, treatment, and prevention. Taxometric statistical methods have been described as being the most suitable approach for answering the class versus continuum question and their use is increasing in mental health research. However, there are many unanswered questions about the use of their use, many of which relate to the item characteristics and/or distributional properties of the variables used in the analyses and how these affect the results. Previous research of this kind is very limited. Thus, more research is needed to determine under what conditions taxometric analyses are appropriate or inappropriate. Toward this goal, we propose a group of computer simulation studies in which we systematically vary pertinent psychometric properties and/or characteristics (such as distributional properties) of the data. We will also examine variables such as sample size and how that affects the stability of results and how different smoothing methods may affect interpretation of graphs produced by the taxometric procedures. If results support the continued use of these methods, in subsequent research, we will examine numerous areas of psychopathology to help determine if there are underlying taxa present.
| Williamson, Donald A; Gleaves, David H; Stewart, Tiffany M (2005) Categorical versus dimensional models of eating disorders: an examination of the evidence. Int J Eat Disord 37:1-10 |
