Clustering as a Preprocessing Tool (Utility) Summarization Preprocessing for regression, PCA, classification, and association analysis Compression Image processing: vector quantization Finding K-nearest Neighbors Localizing search to one or a small number of clusters Outlier detection Outliers are often viewed as those far away from any cluster5 Clustering as a Preprocessing Tool (Utility) ◼ Summarization: ◼ Preprocessing for regression, PCA, classification, and association analysis ◼ Compression: ◼ Image processing: vector quantization ◼ Finding K-nearest Neighbors ◼ Localizing search to one or a small number of clusters ◼ Outlier detection ◼ Outliers are often viewed as those “far away” from any cluster