Reliability of the international IQ test
In this study, 66032 results were randomly selected in order to represent the world population (based on the world population percentage per country in the beginning of 2023) in 3 different years (2020, 2021, and 2022). Enough data was available to represent 82.54% of the world population in the three different years. For the remaining 17.46% there were not enough data to include them properly in the study, so they were ignored. But they shouldn’t do a significant change in the overall results.
The overall results of all three years, when rounded to the unit, are a standard deviation of around 15, and an average IQ of around 100.
This suggests statistically that this IQ test can provide an effective indication of an individual's IQ score (at least to within a few points) using the Raven matrix method. Probably more than most other tests on internet (if not all). But of course: the results of this test should be taken as an indication and do not replace a psychological consultation.