THE MULTIDIMENSIONAL HEALTH LOCUS OF CONTROL SCALE: PSYCHOMETRIC PROPERTIES AND FORM EQUIVALENCE.

This study examined the psychometric equivalence of Forms A and B of the Multidimensional Health Locus of Control Scale in a sample of college students (N = 370; M = 19.5 yr.; 318 Caucasians; 281 women). Given the dearth of studies that address the issue of form equivalence directly, this study sought to ascertain whether these forms could be used interchangeably by researchers. Subscales on the two forms had fairly high correlations (range of r = .77-.81), and similar alpha and omega reliability coefficients. Additionally, confirmatory factor analysis revealed both forms fit a three-factor model well. However, paired-sample t tests yielded significant mean differences for all three subscales. Furthermore, the two forms yielded inconsistent associations with relevant measures. Although the observed pattern of associations with social desirability and safe swimming behaviors were similar for Forms A and B, the pattern of differences was not identical for smoking groups and bicycle helmet use groups between forms. Overall, these results suggested that Forms A and B do not meet the strict criteria for parallel forms, but instead should be considered alternative forms.