document data show that, in terms of entropy, K-CAP can perform substantially better than the standard bisecting k-means algorithm when the data sets contain clusters of widely different sizes – the typical situation. Furthermore, because hyperclique patterns can be found much more efficiently than other types of association patterns, K-CAP retains the appealing computational efficiency of bisecting k-means.
Jiang et al. (2005) points out that pattern-based clustering has broad applications in microarray data analysis, customer segmentation, e-business data analysis, etc. However, pattern-based clustering often returns a large number of highly-overlapping clusters, which makes it hard for users to identify interesting patterns from the mining results. Moreover, pattern-based clustering lacks a general model. Different kinds of patterns or different measures on the pattern coherence may require different algorithms. They address the above two problems by proposing a general quality-driven approach to mining top-k quality pattern-based clusters. They examine the quality-driven approach using real world microarray data sets. The experimental results show that their method is general, effective and efficient.
Second, scholarly interest in free shipping appears to be increasing, perhaps because scholars have started to realize the importance of free shipping promotions in driving customer shopping behavior on the Internet. From a scholarly perspective, there is one significant paper that has appeared.
Lewis et al. (2006) provides an empirical study on the impact of shipping and handling charges on consumer purchasing behavior. Using a database from an online retailer that has experimented with a wide variety of shipping-fee schedules, they investigate the impact of shipping charges on order incidence and order size. They use an ordered probability model that is generalized to account for the effects of nonlinear and discontinuous shipping fees on purchasing decisions, and to accommodate heterogeneity in response parameters. Results show that consumers are very sensitive to shipping charges and that shipping