REVIEW OF METHODS FOR TRANSFORMATION SKINFOLDS DATA TO NORMALITY FOR BOYS AND GIRLS FROM 7 TO 19 YEARS OLD

The most popular method to estimate fatness is anthropometry, especial ly measurement of skinfold thicknesses. However, such kind of data ser iously departs from normal distribution. The present study reviews som e methods not age or sex dependent for normalizing triceps and subscap ular skinfolds data distribution. Material consists 1408 boys and 1390 girls aged 7-19 from Warsaw measured in 1987-88. The following method s were tested: Log(x), log(x-c), -1/x, -1/root x. Approximation to the normality were judged by means of the Shapiro-Wilks W test. The resul ts indicate that log(x-c) gave the best transformation of triceps skin fold for boys and girls. The best method for subscapular site appeared -1/x for boys and -1/root x for girls. The most popular log(x) is not sufficient for correct normalization. Nevertheless, none of methods h ave brought required distribution in each age class. It is suggested, depending on the character of material being transformed, to use all r eviewed methods in, order to achieve proper distribution in each age c lass.