“…An allocation rule based on the estimated posterior probabilities can then be found for assigning the observations to the various populations. The properties of the mixture approach have been considered by Day (1969), Wolfe (1970), Hosmer (1973, O'Neill (1978), Ganesalingam and McLachlan (1978, 1980a,b, 1981, Aitkin (1980), Mezzich and Solomon (1980), Aitkin et al (1981), Symons (1981), Everitt and Hand (1981), and McLachlan (1982), among others. Hawkins et al (1982) strongly supported the increasing emphasis on such an approach to clustering because it is model based.…”