Internal consistency reliabilities (Cronbach’s Alpha) were computed on samples 1 and 5 from the standardisation exercise. The coefficients are computed over both the combined males and females for each relevant sample. The table below provides these coefficients separately for each sample and for the entire normative sample.
15FQ™ Internal Consistencies & Item Total Correlations (ITC's)
addition, the mean 'corrected' item-total correlations for each scale are
also reported for each of these samples.
These parameters index the average association between the constituent
items within a scale and the scale score itself.
Each individual item-scale score coefficient is corrected for the inflation
of the coefficient due to the item's inclusion in the scale score.
The above table
provides the number of items which make up each scale.
This table shows that all the 15FQ™ dimensions have internal consistency reliability
coefficients above .64 indicating that the test dimensions have an acceptable
level of reliability. It can
be seen that the reliabilities hold up quite well across the two sub groups
reported above. The reliability
of these scales compares very favourably with the reliability coefficients
reported in the user manuals for both the OPQ and 16PF.
As a number of authors have noted many of the 16PF factors are very
unreliable with few of the alpha coefficients being greater than .7 and many
in fact being lower than .5. Similarly
the majority of the scales in the OPQ Concept and Factor models have alpha
coefficients of less than .6 and a number have alpha's of less than .5.
following table provides a comparison
of the reliabilities of the 15FQ™ scales with the comparable scales of the
16PF-A, 16PF-C and 16PF-5. The
16PF-A sample consisted of 1785
management applicants, the form C sample of 131 undergraduates, while the
15FQ™ sample is the total standardisation sample for the 15FQ™.
As can be seen, only one 16PF-A scale (Tense) is more reliable than
its 15FQ™ counterpart. The
16PF-A reliabilities range between 0.18 and 0.78, this compares with a range
of 0.60 to 0.87 for 16PF-5 and
0.65 to 0.79 for the 15FQ™.
Comparison of 16PF-A, 16PF-C, 16PF-5 & 15FQ™
|16PF Labels||16PF-A||16PF-C||16PF-5||15FQ™||15FQ™ Labels|
The next table displays
temporal consistency data for the 15FQ™.
Both short-term (2 weeks), obtained
from a sample of 80 undergraduates, and long-term (4 months) from a sample
of 83 volunteers. This table demonstrates that the 15FQ™, has a high degree of
temporal consistency over the periods reported. These test-retest coefficients compare highly favourably with
those reported for similar personality instruments. The short-term SEMs are all well below 1 sten.
Short & Long-term Test-Retest Coefficients for the 15FQ™ (N=80, N=83)
|15FQ™ Scales||Short-term Test-retest||Long-Term Test-retest||Short-term SEM||Long-term SEM|
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