Overall, our experiments underline the effectiveness of our approach, in particular our outcomes indicate that named entity recognition is instrumental in structuring and recognizing 2-5 terms effective queries. Furthermore, we carry out experiments considering and ignoring question bodies, and we show that profiting only from question titles is more promising, but most effective queries are harder to detect. Conversely, adding question bodies makes the retrieval of past related questions noisier, but their content helps to generalize models capable of identifying more effective candidates. (C) 2017 Elsevier Ltd. All rights reserved.