an examination of the factor structure of the psychopathy checklist

There was also a limitation with the software program (i.e, Amos) used to perform
the CFA and SEM analyses. Amos does not permit analyses of polychoric correlations,
which adjust for lack of normality in item-level data. As described earlier, I used the GLS
estimation procedure which relies on regular correlation matrices as it was
recommended by both Tabachnik and Fidell (2007) and Hu et al. (1992) when data are
non-normal. This method is, although better than the standard ML estimation procedure,
still limited in that it also requires large samples.
Finally, although our sample is comparable in size to existing studies examining
the factor structure of the PCL:YV among female youth, it is still not very large. Given
the large number of parameters to be estimated in the two-factor (52), three-factor (42),
and four-facet (60) models, it is plausible that our study was underpowered. Indeed,
even to include 5 participants per parameter estimated, would suggest obtaining 260,
210, and 300 participants, respectively. Therefore, these data are certainly not definitive
and additional research should include, if at all feasible, larger samples of female youth.
4.2 Conclusion
The current study was the first empirical, large-scale Canadian study of generally
violent female youth offenders, and one of the largest studies to have included females
in North America. These females were aged 12 to 17 and the majority were Caucasian.
The author examined the factor structure of the PCL:YV and investigated the
relationship between psychopathy and the use of instrumental aggression.
This study is one of few to have examined the factor structure of the PCL:YV
among adolescents, and the first to examine the three primary factor models
simultaneously among a large Canadian sample of female youth violent offenders.
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