1. A method for discovering significant patterns from a list of records in a dataset, wherein each record comprises a set of items and each significant pattern includes a subset of items such that a significance of the pattern exceeds a significance level, the method comprising the steps of: computing a significance for each item in the list of records to determine significant items; sampling the records randomly to select a sample portion of the records; identifying ambiguous patterns against the sample portion of the records; and verifying the ambiguous patterns against the entire list of records in the dataset.