Item response theory scoring and the detection of curvilinear relationships.

Psychologists are increasingly positing theories of behavior that suggest psychological constructs are curvilinearly related to outcomes. However, results from empirical tests for such curvilinear relations have been mixed. We propose that correctly identifying the response process underlying responses to measures is important for the accuracy of these tests. Indeed, past research has indicated that item responses to many self-report measures follow an ideal point response process-wherein respondents agree only to items that reflect their own standing on the measured variable-as opposed to a dominance process, wherein stronger agreement, regardless of item content, is always indicative of higher standing on the construct. We test whether item response theory (IRT) scoring appropriate for the underlying response process to self-report measures results in more accurate tests for curvilinearity. In 2 simulation studies, we show that, regardless of the underlying response process used to generate the data, using the traditional sum-score generally results in high Type 1 error rates or low power for detecting curvilinearity, depending on the distribution of item locations. With few exceptions, appropriate power and Type 1 error rates are achieved when dominance-based and ideal point-based IRT scoring are correctly used to score dominance and ideal point response data, respectively. We conclude that (a) researchers should be theory-guided when hypothesizing and testing for curvilinear relations; (b) correctly identifying whether responses follow an ideal point versus dominance process, particularly when items are not extreme is critical; and (c) IRT model-based scoring is crucial for accurate tests of curvilinearity. (PsycINFO Database Record

Employee adiposity and incivility: establishing a link and identifying demographic moderators and negative consequences.

The prevalence of increased adiposity among employees in the American workplace has resulted in significant economic costs to organizations. Unfortunately, relatively little research has examined the effects of excess adiposity on employees themselves. As a step toward remedying this, the current study examined a previously unknown link between adiposity and incivility, and how this might impact employee burnout and withdrawal. A student sample was used to initially establish a link between incivility and adiposity, and an applied sample of employees from across the United States was used to more fully test the relationships among incivility, adiposity, burnout, and withdrawal. Finally, the moderating effects of sex and race on these relationships were examined. Preliminary data from 341 student employees revealed that being overly adipose was related to greater reports of workplace incivility, with the effect strongest for those classified as obese. An interaction between sex and adiposity was also found, as well as a three-way interaction among sex, race, and adiposity. These relationships were replicated using a nationwide sample of 528 full-time employees. An interaction between race and adiposity was also found in this second sample. Finally, a model was tested in which incivility was shown to partially mediate the positive relationship between adiposity and the outcome of withdrawal, with both sex and race acting as moderators. Theoretical and practical implications of the findings and future directions are discussed.