Performing Taxometric Analysis to Distinguish Categorical and Dimensional Variables

A fundamental question facing clinical scientists is whether the constructs they are studying are categorical or dimensional in nature. The taxometric method was developed expressly to answer this question and is being used by a growing number of investigators to inform theory, research, and practice in psychopathology. The current paper provides a practical introduction to the method, updating earlier tutorials based on the findings of recent methodological studies. We offer revised guidelines for data requirements, indicator selection, parameter estimation, and procedure selection and implementation. We illustrate our recommended approach to taxometric analysis using idealized data sets as well as data sets representative of those found in clinical research. We close with advice to help newcomers get started on their own taxometric analyses.