DIAGNOSIS OF MULTICOLLINEARITY - ASSESSMENT OF THE CONDITION OF CORRELATION-MATRICES USED IN GENETIC-STUDIES

Data from samples of bean plant genotypes, assessed in a trial carried out in the agricultural year 1991/92 in Vicosa, MG, were used to stud y multicollinearity. Different methods to diagnose the problem were ap plied to correlation matrices. The adverse consequences of multicollin earity become evident as it increases, because the variance associated with the estimates of the parameters increases simultaneously, making them less reliable. For the diagnosis of multicollinearity, the infor mal methods give only general guidance, and a combination of methods b ased on the estimation of the variance inflating factors and variance splitting allows not only quantification of the intensity of multicoll inearity but also identification of the variables involved.