Generating Query Suggestions to Support Task-Based Search
Table 1. Comparison of query suggestion generators across the different types of sources. Statistical significance is tested against the corresponding line in the top block.
['[ITALIC] P( [ITALIC] q| [ITALIC] q0, [ITALIC] s, [ITALIC] k)', '[ITALIC] S', '2015 ERR-IA', '2015  [ITALIC] α-NDCG', '2016 ERR-IA', '2016  [ITALIC] α-NDCG']
The document importance is set to be uniform. We report performance separately for each of the four source types S (that is, we set P(s) uniformly among sources s∈S and set P(s)=0 for s∉S). It is clear that, with a single exception (2015 WH), it is better to use the raw keyphrases, without any expansion. The differences are significant on the 2016 query set for all source types but QS. Regarding the comparison of different source types, we find that QS > WS > WD > WH on the 2016 query set , meanwhile for 2015, the order is WS > WD > QS, WH.