[Analysis of the effect of 2 criteria in the creation of age groups on the value spread of selected somatic parameters].

In the paper we present the results from the statistic analysis of the effect of two age-group creation criterions (1-st criterion--f.e. the 7 years old--from 6,500 to 7,499 years, 2-nd criterion--f.e. the 7 years old--from 7,000 to 7,999) on value dispersion of somatic characteristics chosen. We analyzed the body weight and body height in the set consists of 846 Gypsy children from 7 to 13 years of age. The dispersions of individual values of parameters followed for both criterions were tested by F-test, average values by un-pair Student's t-test. We found that the both criterions have no effect on value dispersion of evaluated somatic characteristics, except of two cases. Further, average values of testing parameters by criterion No. 1 are somewhat lower in comparison with those by criterion No. 2. Statistically significant differences are however incidental and rare. We suggest that in the case of population studies concerning with body growth and development it is possible to compare the sets with different age-group creation criterions.