Data clustering is the process of placing data items into groups so that items within a group are similar and items in different groups are dissimilar. The most common technique for clustering numeric ...

In this paper we propose a dimension-reducing k-means clustering procedure based on a projection pursuit (PP) technique. The clustering structure of high-dimensional data in terms of low-dimensional ...

A behind-the-scenes blog about research methods at Pew Research Center. For our latest findings, visit pewresearch.org. Identifying causal relationships from observational data is not easy. Still, ...