Report on the CLEF-IP 2013 Experiments: Multilayer Collection Selection on Topically Organized Patents

This technical report presents the work which has been carried out using Distributed Information Retrieval methods for federated search of patent documents for the passage retrieval starting from claims (patentability or novelty search) task. Patent documents produced worldwide have manually-assigned classification codes which in our work are used to cluster, distribute and index patents through hundreds or thousands of sub-collections. For source selection, we tested CORI and a new col- lection selection method, the Multilayer method. We also tested CORI and SSL re- sults merging algorithms. We run experiments using different combinations of the number of collections requested and documents retrieved from each collection. One of the aims of the experiments was to test older DIR methods that characterize differ- ent collections using collection statistics like term frequencies and how they perform in patent search and in suggesting relevant collections. Also to experiment with Multi- layer, a new collection selection method that follows a multilayer, multi-evidence process to suggest collections taking advantage of the special hierarchical classifica- tion of patent documents. We submitted 8 runs. According to PRES @100 our best DIR approach ranked 6th across 21 submitted results.