Dipartimento di Ingegneria informatica, automatica e gestionale

Search Engines represents an important application of Information Retrieval. In particular, a major branch of Search Engines is devoted to web search. In this document we summarize our work to produce a submission for the CLEF LongEval initiative [1], primarily concerning web search. The described activity first focuses onto the development of an indexing and searching IR system with the best possible performance based on the provided training data then evaluates its performance on test data coming from different scenarios. We first introduce the task and related problems. Subsequently we present the retrieval systems that we have used for the program submission. Afterwards, we discuss the results obtained with the various systems and compare them in the training scope to explain why some systems perform better than others. Finally, metrics analysis is extended to the additional scenarios LongEval focuses on, along with statistical considerations over the systems’ output.