Table 6.

Results of the exploration of which text field to use as a question.

Passages-based system
Question field	NDNS-Partial	NDNS-Relaxed	NDNS-Exact
query	0.1938	0.1946	0.2225
question	0.2178	0.2177	0.2482
background	0.2147	0.2160	0.2474
query+question	0.2200	0.2203	0.2510
question+background	0.2173	0.2176	0.2477

Document-based system
Question field	NDNS-Partial	NDNS-Relaxed	NDNS-Exact
query	0.2188	0.2195	0.2489
question	0.3044	0.3051	0.3411
background	0.2538	0.2554	0.2837
query+question	0.2833	0.2844	0.3195
question+background	0.2652	0.2659	0.2965