Many supervised and unsupervised learning algorithms are very sensitive to the choice of an appropriate distance metric. While classification tasks can make use of class label information for metric learning, such information is generally unavailable in conventional clustering tasks. Some recent research sought to address a variant of the conventional clustering problem called semi-supervised clustering, which performs clustering in the presence of some background knowledge or supervisory

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... ation expressed as pairwise similarity or dissimilarity constraints. However, existing metric learning methods for semisupervised clustering mostly perform global metric learning through a linear transformation. In this paper, we propose a new metric learning method which performs nonlinear transformation globally but linear transformation locally. In particular, we formulate the learning problem as an optimization problem and present two methods for solving it. Through some toy data sets, we show empirically that our locally linear metric adaptation (LLMA) method can handle some difficult cases that cannot be handled satisfactorily by previous methods. We also demonstrate the effectiveness of our method on some real data sets.