Exploiting a support-based upper bound of Pearson's correlation coefficient for efficiently identifying strongly correlated pairs

  • Authors:
  • Hui Xiong;Shashi Shekhar;Pang-Ning Tan;Vipin Kumar

  • Affiliations:
  • University of Minnesota;University of Minnesota;Michigan State University;University of Minnesota

  • Venue:
  • Proceedings of the tenth ACM SIGKDD international conference on Knowledge discovery and data mining
  • Year:
  • 2004

Quantified Score

Hi-index 0.00

Visualization

Abstract

Given a user-specified minimum correlation threshold θ and a market basket database with N items and T transactions, an all-strong-pairs correlation query finds all item pairs with correlations above the threshold θ. However, when the number of items and transactions are large, the computation cost of this query can be very high. In this paper, we identify an upper bound of Pearson's correlation coefficient for binary variables. This upper bound is not only much cheaper to compute than Pearson's correlation coefficient but also exhibits a special monotone property which allows pruning of many item pairs even without computing their upper bounds. A Two-step All-strong-Pairs corrElation que Ry (TAPER) algorithm is proposed to exploit these properties in a filter-and-refine manner. Furthermore, we provide an algebraic cost model which shows that the computation savings from pruning is independent or improves when the number of items is increased in data sets with common Zipf or linear rank-support distributions. Experimental results from synthetic and real data sets exhibit similar trends and show that the TAPER algorithm can be an order of magnitude faster than brute-force alternatives.