Efficiency of the determinant method of estimating gene frequencies in three allelic models.

Efficiency of three different methods: Bernstein's, maximum likelihood and determinant method were compared. A relative efficiency calculated as a ratio of variances of estimators was used for the comparison. It was shown that the determinant method is almost as efficient for estimating of recessive gene frequency as the method of maximum likelihood, and more efficient than the Bernstein's method.

Valuation of characteristics of water purity. III. The use of numerical methods for qualitative and quantitative evaluation of the degree of pollution.

The taxonometric methods of centrifugal correlation and principal components were used to classify sites along the investigated river with respect to quantity and quality of pollution. The degree of pollution was determined with the use of a collection of microbiological, hydrobiological and chemical characteristics selected by statistical methods.

Valuation of characteristics of water purity. II. The use of numerical methods for the taxonomic appreciation of selected characteristics of water purity.

Numerical methods have been employed to determine the taxonomic value of a number of microbiological, hydrobiological and chemical characteristics of water purity either in current use or proposed. Numerical methods have at the same time served to evaluate the usefulness and correlation coefficients of these characteristics in classification of the degree of pollution in different stretches (sites) of rivers.