an examination of the factor structure of the psychopathy checklist

3 Results
3.1 Coding Reliability
Inter-rater reliability coding was conducted on 15% of the sample for PCL:YV
ratings. The files that were double-coded were randomly selected from the sample.
Absolute agreement internal consistency correlations were computed for total (α = .90),
Factor 1 (α = .79), Factor 2 (α = .91), Facet 1 (α = .79), Facet 2 (α = .84), Facet 3 (α =
.81) and Facet 4 (α = .88) psychopathy scores (ps ≤ .001). Cohen’s Kappa was
calculated to determine consistency among raters’ absolute agreement in the
classification of offenders as either high (score above 25) or low (score of 24 or below)
psychopathy based on the cut score of 25. This value indicated almost perfect
agreement between raters, k = .81, p < .001. Cohen’s Kappa was also calculated to
determine consistency among raters in the classification of offenders based on the cut
score of 30. This value indicated moderate agreement between the raters, k = .53, p =
.002. Further, Cohen’s Kappa was calculated to determine consistency among raters in
classifying offenders categorically (low: score of 0-19, moderate: score of 20-29, high:
score of 30-40). The value obtained indicated substantial agreement between raters, k =
.61, p < .001.
Fifteen percent of the sample was also double-coded to verify that the
instrumentality variables were coded reliability. Absolute agreement internal consistency
correlations were calculated for the continuous instrumentality variable, α = .89, p <
.001. Absolute internal consistency correlations were also calculated for each item and
were as follows: (1) planning (α = .64), (2) goal directed (α = .68), (3) unprovoked (α =
.61), (4) lack of anger (α = .97), and (5) stranger (α = .78), (ps ≤ .003).
36