Abstract: Improved privacy preservation techniques are disclosed for use in accordance with data mining. By way of example, a technique for preserving privacy of data records for use in a data mining application comprises the following steps/operations. Different privacy levels are assigned to the data records. Condensed groups are constructed from the data records based on the privacy levels, wherein summary statistics are maintained for each condensed group. Pseudo-data is generated from the summary statistics, wherein the pseudo-data is available for use in the data mining application.

Abstract: For mining causality rules in an event database, the rules are obtained by iteratively generating candidate rules and counting their occurrences in the event database. Newly identified causality rules are used to generate the next set of candidate rules to be evaluated, by increasing the size of the set of consequential events triggered by triggering events and/or the number of triggering events. The preferred embodiment uses an iterative approach to deriving the causality rules in order of the consequential set sizes and triggering set sizes. The detection of an occurrence of a causality rule in an event sequence is handled as a sub-sequence matching problem using a novel hierarchical matching method to improve efficiency.