The Construct, Convergent and Divergent Validity, and Reliability of Three Optimism Scales among North American University Students.

The primary objective of this study is to compare the construct, convergent and divergent validity and the reliability of three optimism scales. The study relied on a nonprobability sample of 100 social work students at Western Michigan University in the United States (Seventy-nine percent of the sample were female, and 21% were male). The sample's mean age was 26.35 years, SD = 7.70. Sixty-nine percent (69%) of the respondents self-identified as White, and 31% self-identified as African American, Hispanic/Latino, multiethnic, Native American or Asian American. The study used confirmatory factor and multiple regression analyses (CFA and MRA). The findings show that the Life Orientation Test-Revised (LOT-R) and the Personal Optimism Scale (POS) were supported by three indicators of goodness of fit, while the Brief Interactive Optimism Scale-Garcia (BIOS-G) was supported by eight. The LOT-R showed no acceptable internal consistency indicators, but the POS and the BIOS-G showed several good internal consistency indicators. Correlations of all of these scales with the Physical Well-being Scale-Garcia (PWS-G) ranged from r (100) = .303, p = .002 to r (100) = .439, p = .000. The three scales had divergent validity because their scores did not differ by gender (LOT-R: t(100) = -.885, p = .383; POS: t(100) = -.263, p = .794; BIOS-G: t(100) = -.840, p = .407). The findings suggest the advisability of recommending the BIOS-G, which is short and easy to use and understand.