Use of ICC for defining the optimal clustering solution under normality assumption

The intraclass correlation coefficient r is frequently used to measure the degree of intragroup resemblance (for example of characteristics such as blood pressure, weight and height). A definition of the intraclass correlation coefficient is given on the basis of a normal random effect model. The theory concerning r is wellestablished for single variables analysis (Sheff´e, 1959; Rao, 1973). We propose to consider a multiple test procedure in order to define the optimal clustering solution under normality assumption of the involved variables, using the test of null intraclass correlation.