Page 52 - Special Topic Session (STS) - Volume 4

STS560 James Houran et al.
related than other procedures. Similarly, Rynes and Connerley (1993) found
that the interview was perceived to possess high job-relatedness. Schuler
(1993) suggested that selection methods which are perceived as controllable
by the candidate, obvious in purpose, providing task relevant information, and
offering a means of feedback are considered the most socially-valid or
acceptable. We propose that the validity and effectiveness of the combined
approach in Figure 1 can be bolstered by empirically and procedurally aligning
assessments and interviews to work collectively as a seamless and integrated
process. Using insights gained from psychometrics and data-mining, we
outline one solution that uses empirical insights gleaned from test-takers’
responses. This solution has a long (> 15 years) track record of actual usage in
the area of Human Resources (HR) testing. The approach relies heavily on the
statistical machinery provided by Item Response Theory (IRT), and Rasch
scaling in particular (see van der Linden & Hambleton, 1997).

2. An IRT Approach
The Rasch (1960/1980) latent-trait model uses the simplest IRT where
items are described solely by their difficulty, at least for binary items. In the
case of rating scales, the structure of the rating scale, as described by transition
from one rating to another, has to be taken into account as well. The Rasch
rating scale model is probabilistic and revolves around the log odds of Pijk, i.e.,
the probability that item i will receive from person j the rating k. In particular,

Figure 2: Category structure of hypothetical item (see text).

log ( ) = − − { } (1)
(−1)

In Equation 1,

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