PaWI: ParallelWeighted Itemset Mining by means of MapReduce
Frequent itemset mining is an exploratory data mining technique that has fruitfully been exploited to extract recurrent co-occurrences between data items. Since in many application contexts items are enriched with weights denoting their relative importance in the analyzed data, pushing item weights into the itemset mining process, i.e., mining weighted itemsets rather than traditional itemsets, is an appealing research direction. Although many efficient in-memory weighted itemset mining algorithms are available in literature, there is a lack of parallel and distributed solutions which are able to scale towards Big Weighted Data. This paper presents a scalable frequent weighted itemset mining algorithm based on the MapReduce paradigm. To demonstrate its actionability and scalability, the proposed algorithm was tested on a real Big dataset collecting approximately 34 millions of reviews of Amazon items. Weights indicate the ratings given by users to the purchased items. The mined itemsets represent combinations of items that were frequently bought together with an overall rating above average.