TITLE: Clustering by Partial Mixture Modeling ABSTRACT: Clustering algorithms based upon some form of nonparametric or semiparametric density estimate are of more theoretical interest than some of the distance-based or ad hoc algorithmic procedures. However density estimation is subject to the curse of dimensionality so that care must be exercised. Clustering algorithms are sometimes described as biased when solutions are highly influenced by initial configurations. Mode-finding algorithms are related to but different than gaussian mixture models. In this paper, we describe a hybrid algorithm which finds modes by fitting 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. The clustering results may be examined using an advanced visualization tool such as GGobi. We describe the algorithms, some simulations, and some real experiments.