The Spheres of Control scale: the identification of a clear replicable three-factor structure

The Spheres of Control scale (SOC) is a multidimensional measure of locus of control, originally designed to assess personal control, interpersonal control, and socio-political control. This scale is now in its third revision. Although Versions 1 and 2 have been scrutinised using factor analysis, no published studies have yet examined the factor structure of Version 3. Responses to the original version [SOC-1; Paulhus, D., & Christie, R. (1981). Spheres of control: An interactionist approach to the assessment of perceived control. In H.M. Lefcourts (Ed.) Research with the Locus of Control Construct (Vol. 1) Assessment methods (pp.161–188). New York: Academic Press.] and the most recent version [SOC-3; Paulhus, D., & Van Selst, M. (1990). The spheres of control scale: 10 yrs of research. Personality and Individual Differences, 11, 1029–1036] were provided by a group of 354 university students, and a principal components analysis was undertaken. The results showed a reasonable fit with the SOC construct for the original (SOC-1) scale, but not for the more recent SOC-3. A combination of scales from the two versions provided the best indication of the presence of the three theoretically derived dimensions. In a second study, Confirmatory Factor Analysis was used to examine the three factor model and four competing models. The eight indices of fit derived from the responses of 382 undergraduate students showed that the three factor structure was superior to any of the competing models.