I__. - International Military Testing Association

then by the principle of transitivity (things equal to the same thing are
equal to each other), one might link changes in the surrogate with changes in
the operational performance about which one wished to make statements.
Dose Equivalency
A second methodology that can be employed in studies of real-world
performance is called “dose equivalency.” Dose Equivalency is a strategy used
in conjunction with surrogate measures in order to quantify degradation of
operational performance by selecting an indexing agent(s) or treatment and a
set of target performance tasks. Then graded “dosages” of the indexing agent
are administered and performance decrements as a function of the indexing
agent are marked or calibrated against the various dosages. One is left with
a functional relationship between an agent and performance(s).
This strategy has been applied in a study we conducted using different
dosages of orally-administe,red alcohol (Kennedy, Baltzley, Lane, Wilkes, &
Smith, 1989). Alcohol was selected as the indexing agent for several
reasons : 1) alcohol is known to be a global depressant, having wide-ranging
and well-documented impacts on performance and operational readiness has been
directed to the identification and calibration of what are to be considered
“safe” and “unsafe” doses of this agent, 3) equipment and assay procedures are
readily available for calibrating both blood alcohol levels (BALI and alcohol
detected in expired breath (breathalyzer) and 4) because alcohol is widely
used, it is feasible to administer to male subjects who, by self-report, use
alcohol to a moderate degree, thereby obviating potential threat to volunteers
and meeting requirements for ethical treatment of subjects in human
experimental research.
EXPERIMENT 1 - APTS AS SURROGATE FOR ASVAB SUBTEST
In this analysis, 16 women and 11 men ranging in age from 18 to 38 were
tested with a synthetic Armed Services Vocational Aptitude Battery (ASVAB)
(Steinberg, 1986), and the microcomputer-based assessment used was the
Automated Performance Test System (APTS), which is fully described in Kennedy
et al. (1989). Seven of the tests used were from the original APTS (Pattern
Comparison: Two-Finger and Nonpreferred Hand Tapping: Code Substitution:
Simple Reaction Time: Grammatical Reasoning: and Manikin) and four additional
subtests were selected from the Unified Tri-Service Committee Performance
Assessment Battery (UTC-PAB) (Englund, Reeves, Shingledecker, Thorne, Wilson,
h Hegge, 1987).
The most dramatic findings were the consistently high reliabilities of the
battery subtests; the smallest reliability was 0.85, which in our judgment is
sufficient for statistical power and differential purposes.
Scores on the performance battery were averaged across the seven trials
and then correlated with the subscales and total score from the ASVAB.
Multiple regression was used to examine the predictive power of the battery as
a whole on the total ASVAB criterion. The multiple R was 0.94 (R2 = 0.881,
and, even when corrected for shrinkage, the multiple H was 0.88. This
indicates that when shrinkage owing to the particular sample used is taken
into account, 7’1% of the ASVAB variance is explained by performance on the
battery subtests.
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