Background. The emergence of the psychometric tradition in Russian psychology necessitates a thorough exploration and adoption of the international experience in the development of appropriate measurement instruments and methodologies. The goal of the present study was thus to perform a comprehensive evaluation of the International Cognitive Ability Resource (ICAR) instrument in a Russian sample. The modified ICAR instrument consisted of visuo-spatial subtests Three-dimensional Rotation, Mental Reasoning (original ICAR subtests), as well as the previously developed verbal subtests Mill-Hill verbal scale and Analogies (from the ROADS test battery).

Design. The ICAR battery was administered to n=681 individuals (377 females) in the age from 17 to 59 years (Med=23, M=25.83, SD=7.58 лет) who were either college students or adults with a college degree from the city of Moscow who volunteered for the study. The test battery was administered without (n=284) as well as with (n=397) a time limit.

Results. The study demonstrated adequate psychometric properties of the modified ICAR battery, and revealed a fundamentally bifactor structure of the battery both at the level of individual items as well as at the level of subtests. Thus, individual’s performance on each item or subtest can be conceptualized as being driven by specific (e.g., fluid or verbal) as well as general (g) intelligence factors. We also show that introducing the time limit distorts the psychometric structure of the battery, lowers internal consistency, and reduces the g-saturation of the resulting scores, a finding that has important implications for the theory and practice of testing.