Algorithms for Mining Distance-Based Outliers in Large Datasets.

Edwin M. Knorr, Raymond T. Ng: Algorithms for Mining Distance-Based Outliers in Large Datasets. VLDB 1998: 392-403
  author    = {Edwin M. Knorr and
               Raymond T. Ng},
  editor    = {Ashish Gupta and
               Oded Shmueli and
               Jennifer Widom},
  title     = {Algorithms for Mining Distance-Based Outliers in Large Datasets},
  booktitle = {VLDB'98, Proceedings of 24rd International Conference on Very
               Large Data Bases, August 24-27, 1998, New York City, New York,
  publisher = {Morgan Kaufmann},
  year      = {1998},
  isbn      = {1-55860-566-5},
  pages     = {392-403},
  ee        = {db/conf/vldb/KnorrN98.html},
  crossref  = {DBLP:conf/vldb/98},
  bibsource = {DBLP,}


This paper deals with finding outliers (exceptions) in large, multidimensional datasets. The identification of outliers can lead to the discovery of truly unexpected knowledge in areas such as electronic commerce, credit card fraud, and even the analysis of performance statistics of professional athletes. Existing methods that we have seen for finding outliers in large datasets can only deal efficiently with two dimensions/attributes of a dataset. Here, we study the notion of DB- (Distance- Based) outliers. While we provide formal and empirical evidence showing the usefulness of DB-outliers, we focus on the development of algorithms for computingsuch outliers.

First, we present two simple algorithms, both having a complexity of O(k N2), k being the dimensionality and N being the number of objects in the dataset. These algorithms readily support datasets with many more than two attributes. Second, we present an optimized cell-based algorithm that has a complexitythat is linear wrt N, but exponential wrt k. Third, for datasets that are mainly disk-resident, we present another version of the cell-based algorithm that guarantees at most 3 passes over a dataset. We provide experimental results showing that these cell- based algorithms are by far the best for k <=4.

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Ashish Gupta, Oded Shmueli, Jennifer Widom (Eds.): VLDB'98, Proceedings of 24rd International Conference on Very Large Data Bases, August 24-27, 1998, New York City, New York, USA. Morgan Kaufmann 1998, ISBN 1-55860-566-5
Contents BibTeX


Andreas Arning, Rakesh Agrawal, Prabhakar Raghavan: A Linear Method for Deviation Detection in Large Databases. KDD 1996: 164-169 BibTeX
Rakesh Agrawal, Sakti P. Ghosh, Tomasz Imielinski, Balakrishna R. Iyer, Arun N. Swami: An Interval Classifier for Database Mining Applications. VLDB 1992: 560-573 BibTeX
Rakesh Agrawal, Tomasz Imielinski, Arun N. Swami: Mining Association Rules between Sets of Items in Large Databases. SIGMOD Conference 1993: 207-216 BibTeX
Inderpal S. Bhandari, Edward Colet, Jennifer Parker, Zachary Pines, Rajiv Pratap, Krishnakumar Ramanujam: Advanced Scout: Data Mining and Knowledge Discovery in NBA Data. Data Min. Knowl. Discov. 1(1): 121-125(1997) BibTeX
Jon Louis Bentley: Multidimensional Binary Search Trees Used for Associative Searching. Commun. ACM 18(9): 509-517(1975) BibTeX
Martin Ester, Hans-Peter Kriegel, Jörg Sander, Xiaowei Xu: A Density-Based Algorithm for Discovering Clusters in Large Spatial Databases with Noise. KDD 1996: 226-231 BibTeX
Antonin Guttman: R-Trees: A Dynamic Index Structure for Spatial Searching. SIGMOD Conference 1984: 47-57 BibTeX
Jiawei Han, Yandong Cai, Nick Cercone: Knowledge Discovery in Databases: An Attribute-Oriented Approach. VLDB 1992: 547-559 BibTeX
Joseph M. Hellerstein, Elias Koutsoupias, Christos H. Papadimitriou: On the Analysis of Indexing Schemes. PODS 1997: 249-256 BibTeX
Edwin M. Knorr, Raymond T. Ng: Finding Aggregate Proximity Relationships and Commonalities in Spatial Data Mining. IEEE Trans. Knowl. Data Eng. 8(6): 884-897(1996) BibTeX
Edwin M. Knorr, Raymond T. Ng: A Unified Notion of Outliers: Properties and Computation. KDD 1997: 219-222 BibTeX
Heikki Mannila, Hannu Toivonen: Discovering Generalized Episodes Using Minimal Occurrences. KDD 1996: 146-151 BibTeX
Heikki Mannila, Hannu Toivonen, A. Inkeri Verkamo: Discovering Frequent Episodes in Sequences. KDD 1995: 210-215 BibTeX
Raymond T. Ng, Jiawei Han: Efficient and Effective Clustering Methods for Spatial Data Mining. VLDB 1994: 144-155 BibTeX
Hanan Samet: The Design and Analysis of Spatial Data Structures. Addison-Wesley 1990
Tian Zhang, Raghu Ramakrishnan, Miron Livny: BIRCH: An Efficient Data Clustering Method for Very Large Databases. SIGMOD Conference 1996: 103-114 BibTeX

Referenced by

  1. Edwin M. Knorr, Raymond T. Ng, V. Tucakov: Distance-Based Outliers: Algorithms and Applications. VLDB J. 8(3-4): 237-253(2000)
  2. Themistoklis Palpanas: Knowledge Discovery in Data Warehouses. SIGMOD Record 29(3): 88-100(2000)
  3. Sridhar Ramaswamy, Rajeev Rastogi, Kyuseok Shim: Efficient Algorithms for Mining Outliers from Large Data Sets. SIGMOD Conference 2000: 427-438
  4. Markus M. Breunig, Hans-Peter Kriegel, Raymond T. Ng, Jörg Sander: LOF: Identifying Density-Based Local Outliers. SIGMOD Conference 2000: 93-104
  5. Minos N. Garofalakis, Rajeev Rastogi, S. Seshadri, Kyuseok Shim: Data Mining and the Web: Past, Present and Future. Workshop on Web Information and Data Management 1999: 43-47
  6. H. V. Jagadish, Nick Koudas, S. Muthukrishnan: Mining Deviants in a Time Series Database. VLDB 1999: 102-113
  7. Edwin M. Knorr, Raymond T. Ng: Finding Intensional Knowledge of Distance-Based Outliers. VLDB 1999: 211-222
  8. Venkatesh Ganti, Johannes Gehrke, Raghu Ramakrishnan: A Framework for Measuring Changes in Data Characteristics. PODS 1999: 126-137
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