Notes
These fit indices are called comparative curve fit indices (CCFIs). One interpretive heuristic that is routinely applied in research is as follows: CCFIs less than .400 indicate the research data are more similar to bootstrapped, simulated data with dimensional latent structure and CCFIs greater than .600 indicate the research data are more similar to bootstrapped, simulated data with taxonic latent structure (Ruscio & Kaczetow, 2009; Ruscio, Walters, Marcus, & Kaczetow, 2010). This is a conservative test. A more liberal, yet still accurate, test, and the one Longpré et al. used, is that CCFIs less than .450 and greater than .550 are interpreted as meaningful.
In MAMBAC, a peak emerges when a “cut” is made along one indicator to group the sample into two groups and this cut provides the optimal separation between the groups on a second indicator. Dichotomous latent structure will therefore produce a curve with a single peak, and dimensional latent structure will produce a U-shaped curve. Trichotomous structure will produce a twin-pealed curve, but shapes will vary depending on other characteristics of the data (see Fig. 1 in McGrath, 2008). In MAXEIG, a peak emerges when a “window” captures a mixture of taxon and complement members, resulting in a high rate of covariance between indicator scores. When a window captures purely complement class or taxon class members, the covariance is low or non-existent, so the eigenvalue is lower. Dimensional data result in U-shaped curves that indicate that there is not much change in eigenvalue, as the windows are capturing roughly equivalent amounts of covariance, with the exception of the leftmost and rightmost windows, causing the tails to rise. Depending on other data characteristics, such as indicator skew, trichotomous latent structure will produce variably shaped MAXEIG curves (see Fig. 3 in McGrath, 2008).
My experience with taxometric analyses and understanding the potential for trichotomous latent structure comes from doing this research.
References
Ahmed, A. O. (2010). Differentiating classes from dimensions under unfavorable data conditions: Monte Carlo comparisons of taxometric and latent variable mixture models. Unpublished doctoral dissertation, University of Southern Mississippi.
American Psychiatric Association. (2013). Diagnostic and statistical manual of mental disorders (5th ed.). Arlington, VA: American Psychiatric Press.
Borsboom, D., Rhemtulla, M., Cramer, A. O. J., van der Maas, H. L. J., Scheffer, M., & Dolan, C. V. (2016). Kinds versus continua: A review of psychometric approaches to uncover the structure of psychiatric constructs. Psychological Medicine,46, 1567–1579. https://doi.org/10.1017/S0033291715001944.
Hanson, R. K. (2010). Dimensional measurement of sexual deviance. Archives of Sexual Behavior,39, 401–404. https://doi.org/10.1007/s10508-009-9575-6.
Knight, R. A., Sims-Knight, J., & Guay, J. P. (2013). Is a separate diagnostic category defensible for paraphilic coercion? Journal of Criminal Justice,41, 90–99. https://doi.org/10.1016/j.jcrimjus.2012.11.002.
Longpré, N., Guay, J. P., Knight, R. A., & Benbouriche, M. (2018). Sadistic offender or sexual sadism? Taxometric evidence for a dimensional structure of sexual sadism. Archives of Sexual Behavior,47, 403–416. https://doi.org/10.1007/s10508-017-1068-4.
McGrath, R. E. (2008). Inferential errors in taxometric analyses of ordered three-class constructs. Journal of Personality Assessment,90, 11–25. https://doi.org/10.1080/00223890701356755.
McPhail, I. V., Olver, M. E., Brouillette-Alarie, S., & Looman, J. (2018). Taxometric analysis of the latent structure of pedophilic interest. Archives of Sexual Behavior,47, 2223–2240. https://doi.org/10.1007/s10508-018-1225-4.
Meehl, P. E. (2004). What’s in a taxon? Journal of Abnormal Psychology,113, 39–43. https://doi.org/10.1037/0021-843X.113.1.39.
Meehl, P. E., & Yonce, L. J. (1994). Taxometric analysis: I. Detecting taxonicity with two quantitative indicators using means above and below a sliding cut (MAMBAC procedure). Psychological Reports,74, 1059–1274.
Meehl, P. E., & Yonce, L. J. (1996). Taxometric analysis: II. Detecting taxonicity using covariance of two quantitative indicators in successive intervals of a third indicator (MAXCOV procedure). Psychological Reports,78, 1091–1227. https://doi.org/10.2466/pr0.1996.78.3c.1091.
Mokros, A., Schilling, F., Weiss, K., Nitschke, J., & Eher, R. (2014). Sadism in sexual offenders: Evidence for dimensionality. Psychological Assessment,26, 138–147. https://doi.org/10.1037/a0034861.
Reale, K. S. (2017). An examination of sadism in sexual homicide: Are investigative awareness and the severity of sadistic behaviour distinctive features? Unpublished master’s thesis, Simon Fraser University.
Ruscio, J., Haslam, N., & Ruscio, A. M. (2006). Introduction to the taxometric method: A practical guide. Mahwah, NJ: Lawrence Erlbaum Associates.
Ruscio, J., & Kaczetow, W. (2009). Differentiating categories and dimensions: Evaluating the robustness of taxometric analysis. Multivariate Behavioral Research,44, 259–280. https://doi.org/10.1080/00273170902794248.
Ruscio, J., & Ruscio, A. M. (2004). A nontechnical introduction to the taxometric method. Understanding Statistics,3, 151–194. https://doi.org/10.1207/s15328031us0303_2.
Ruscio, J., Walters, G. D., Marcus, D. K., & Kaczetow, W. (2010). Comparing the relative fit of categorical and dimensional latent variable models using consistency tests. Psychological Assessment,22, 5–21. https://doi.org/10.1037/a0018259.
Schmidt, A. F., Mokros, A., & Banse, R. (2013). Is pedophilic sexual preference continuous? A taxometric analysis based on direct and indirect measures. Psychological Assessment,25, 1146–1153. https://doi.org/10.1037/a0033326.
Steinley, D., & McDonald, R. P. (2007). Examining factor score distributions to determine the nature of latent spaces. Multivariate Behavioral Research,42, 133–156. https://doi.org/10.1080/00273170701341217.
Stephens, S., Leroux, E., Skilling, T., Cantor, J. M., & Seto, M. C. (2017). Taxometric analyses of pedophilia utilizing self-report, behavioral, and sexual arousal indicators. Journal of Abnormal Psychology,126, 1114–1119. https://doi.org/10.1037/abn0000291.
Waller, N. G., & Meehl, P. E. (1998). Multivariate taxometric procedures: Distinguishing types from continua. Thousand Oaks, CA: Sage.
Walters, G. D., McGrath, R. E., & Knight, R. A. (2010). Taxometrics, polytomous constructs, and the comparison curve fit index: A Monte Carlo analysis. Psychological Assessment,22, 149–156. https://doi.org/10.1037/a0017819.
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McPhail, I.V. Of Dimensions, Dichotomies, and Trichotomies: Comments on the Taxometric Ghost that Haunts Longpré, Guay, Knight, and Benbouriche (2018). Arch Sex Behav 49, 19–23 (2020). https://doi.org/10.1007/s10508-019-01530-y
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DOI: https://doi.org/10.1007/s10508-019-01530-y