3.4.1.1. Measurement properties. The internal-consistency
reliability of a scale composed of the seven
distance scores was determined using Cronbach's alpha.
This reliability was .76 for the Mahalanobis distance
(D2
) and .80 for absolute deviation values (for the two
scoring approaches, r= .95, pb.001), which is comparable
with that of many conventional ability tests
containing more items.
3.4.1.2. Underlying structure. Consistent with
Wagner (1987), the fit of a single-factor model to the
data was tested via confirmatory factor analysis (CFA).
The fit of this model was very good (χ2
(14) = 21.65,
p=.09; CFI =.99; RMSEA =.03, 90% CI =.00–.05),
with loadings of the vignettes on the latent factor
ranging between .50 and .60. The variance accounted