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Accuracy Analysis with Special Reference to the Prediction of Grassland Yield
Author(s) -
Allen O. Brian,
Raktoe B. L.
Publication year - 1981
Publication title -
biometrical journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.108
H-Index - 63
eISSN - 1521-4036
pISSN - 0323-3847
DOI - 10.1002/bimj.4710230404
Subject(s) - statistics , mean squared error , mathematics , multiplicative function , grassland , bivariate analysis , yield (engineering) , ecology , mathematical analysis , materials science , metallurgy , biology
Abstract In this paper techniques are presented which allow the evaluation of accuracy of prediction methods, with special reference to the prediction of grassland yield. The more prominent methods of predicting grassland yield are discussed. Two coefficients, which are normalizations of the mean‐squared‐error, are proposed as measures of accuracy. It is shown that the mean‐squared‐error partitions into the sum of three meaningful components of error. The distribution of the components is discussed under the assumption that the actual and predicted yields have a bivariate normal distribution. The problem of accuracy analysis is addressed when one is only interested in ranking the yields of grassland areas. The ratio of the mean‐squared‐error for two competing prediction methods is investigated. Finally, a multiplicative model is studied which allows predicting ability to differ over time or over regions.