Public Domain Intelligence Tests: Psychometric properties of the Cog15 and ICAR16 cognitive ability scales

Abstract: The current paper aims to explore the psychometric properties of two public domain cognitive ability scales, Cog15 and ICAR16, and investigate how well they each capture the g-factor in a Swedish sample (N = 428). The motivation for choosing these aims is that public domain, free, and easily accessible intelligence tests are needed for measuring the g-factor. Principal components analysis (PCA), confirmatory factor analysis (CFA) with maximum likelihood estimation, and reliability analyses returned results that indicated that ICAR16 is the better tool when measuring the g-factor, since it explained more of the variance (28.3%) and returned better reliability measures (Cronbach’s α = .77, McDonald’s ω = .77). We recommend omitting some of the items from the Cog15 and the ICAR16 scales. Future researchers should replicate the preliminary findings of this study on larger and more diverse samples to further understand the tests at hand, since Cog15 has yet to be researched as of now and ICAR16 is still under-researched.