Cognitive Estimations Test (CET) is becoming a part of many examinations and research studies of executive functions. It is a short, simple and user-friendly test. Authors present two alternative forms of the CET as a supplement to the original Czech version of the test (TKO, Preiss and Laing, 2001). They describe the CET as a suitable instrument for investigation of executive functions in brain lesions of various etiology. Both clinically developed alternative forms have been studied in a sample of 48 subjects without any neurologic or psychiatric morbidity (23 males and 25 females), average age 26.4 years (range 19-55, SD = 8.1). In both tests, the extreme responses were excluded (in version 1, 4.3%, in version 2, 2.8% responses). The authors found a comparability of the items in both forms with respect to gender and a non-significant moderate dependence of the total performance in the test on age (-0.13 in version 1, -0.25 in version 2). For clinical and research evaluation, they converted test performance to weighted scores according to standard deviation limits. As 0 points (performance without conspicuity), they scored performances in the range of one standard deviation away from the mean, as 1 point (moderately conspicous estimation), estimation between one and two standard deviations, and as 2 points (conspicous estimation), estimation beyond the limit of two standard deviations. The average sum of standard scores in version 1 was 3 weighted points (SD = 1.8; variance 0 – 8 points), in version 2, it was 3.5 weighted points (SD = 1.7; variance 0 – 8 points). Correlation of the sums of total scores of both forms is not significant (r = 0.22), when including the extreme responses 0.33 (p = 0.021). Low correlation makes the parallelity of both forms problematic. The effect of education was statistically significant in version 1 (two-sided t-test, p = 0.035), not significant in version 2 (two-sided t-test, p = 0.538). The authors recommend the test for use in clinical practice and in research of executive functions. Further research should aim at independence of the performance on educationand cultural and geographic environment, though mainly at greater balance of both forms of the test. Test performance can also be influenced by personality psychopathology.

        Key words: cognitive estimations test, CET, executive function.