ECNU at 2018 eHealth Task 2: Technologically assisted reviews in empirical medicine

The 2018 CLEF eHealth Task 2 has two sub-tasks in order to write a systematic review of evidence-based medicine. Researchers are required to retrieve relevant documents given by medical database for each query (sub-task 1) and re-rank the documents with the results of the Boolean search as the starting point (sub-task 2). We adopt BM25 with query expansion to acquire basic relationship and utilize a customized Paragraph2Vector to represent queries /documents trained by the training set of Boolean search. To compute the relevant score of given query-document pair, cosine similarity and logistic regression are taken in our experiments. Finally, we find that the combination has a better performance.