Biomedical subjects

Stephen Stark

Publications and source records attributed to Stephen Stark.

3 recordsLinked to original sources

PubMed2006

Examining assumptions about item responding in personality assessment: should ideal point methods be considered for scale development and scoring?

The present study investigated whether the assumptions of an ideal point response process, similar in spirit to Thurstone's work in the context of attitude measurement, can provide viable alternatives to the traditionally used dominance assumptions for personality item calibration and scoring. Item response theory methods were used to compare the fit of 2 ideal point and 2 dominance models with data from the 5th edition of the Sixteen Personality Factor Questionnaire (S. Conn & M. L. Rieke, 1994). The authors' results indicate that ideal point models can provide as good or better fit to personality items than do dominance models because they can fit monotonically increasing item response functions but do not require this property. Several implications of these findings for personality measurement and personnel selection are described.

Data Interpretation, Statistical↗

PubMed2006

Detecting differential item functioning with confirmatory factor analysis and item response theory: toward a unified strategy.

In this article, the authors developed a common strategy for identifying differential item functioning (DIF) items that can be implemented in both the mean and covariance structures method (MACS) and item response theory (IRT). They proposed examining the loadings (discrimination) and the intercept (location) parameters simultaneously using the likelihood ratio test with a free-baseline model and Bonferroni corrected critical p values. They compared the relative efficacy of this approach with alternative implementations for various types and amounts of DIF, sample sizes, numbers of response categories, and amounts of impact (latent mean differences). Results indicated that the proposed strategy was considerably more effective than an alternative approach involving a constrained-baseline model. Both MACS and IRT performed similarly well in the majority of experimental conditions. As expected, MACS performed slightly worse in dichotomous conditions but better than IRT in polytomous cases where sample sizes were small. Also, contrary to popular belief, MACS performed well in conditions where DIF was simulated on item thresholds (item means), and its accuracy was not affected by impact.

Discrimination, Psychological↗

PubMed2004

Examining the effects of differential item (functioning and differential) test functioning on selection decisions: when are statistically significant effects practically important?

Item response theory differential test functioning (DTP) methods are often used to address issues in personnel selection, but the results are frequently difficult to interpret because statistically significant findings may have little practical importance. In this article, the authors proposed 2 effect size measures for DTP. One related DTP to mean raw score differences across groups: the other related DTP to the 4/5th rule for adverse impact at successive cut scores. The effects of DTP were examined in the context of personality assessment, professional licensure, and college admissions. Overall, the result indicated that although many items exhibited bias in analyses of the large samples, the net magnitudes of effect on potential selection decisions were nugatory.

College Admission Test↗