TITLE: Gaussian Mixture Estimation With Incomplete Models ABSTRACT: A common use of mixture modeling in multivariate data is for the estimation of clusters. The practical difficulty is the determination of the correct number of components in the mixture model. This choice is confounded by the need for reasonable initial guesses for the parameters for each mixture component. In this paper, we describe a hybrid algorithm which attempts to fit incomplete mixture models, or partial mixture component models. Bias problems are avoided since the partial mixture model is fitted many times using carefully chosen random starting guesses. Clustering the results of these many fits using an advanced visualization tool such as GGobi can reveal individual components. We describe the algorithms, some simulations, and some real experiments.