Table 2.

Test collection’s information about the collection size $|\mathcal{D}|$, number of terms $|\mathcal{T}|$, collection length $l_c$, average document length ${\overline{l}}_d$, average verboseness ${\overline{v}}_d$, elite average verboseness ${\breve{v}}_d$, average term length ${\overline{l}}_t$, average burstiness ${\overline{b}}_t$, and elite average burstiness ${\breve{b}}_t$

Corpus	EC	Challenge	$|\mathcal{D}|$	$|\mathcal{T}|$	$l_c$
			${\overline{l}}_d$	${\overline{v}}_d$	${\breve{v}}_d\downarrow$
			${\overline{l}}_t$	${\overline{b}}_t$	${\breve{b}}_t$
Aquaint	TREC	HARD’05	1,033,461	647,280	282,858,247
			273.700	436.995	1.519
			436.995	273.700	1.384
Disks 4&5	TREC	Ad Hoc 8	528,106	737,963	156,226,039
			295.823	211.699	1.575
			211.699	295.823	1.377
eHealth’14	CLEF	eHealth’14	1,104,298	1,103,947	685,458,908
			620.917	308.294	1.900
			308.294	620.917	1.349
.GOV	TREC	Web’02	1,214,592	2,937,251	1,770,120,644
			1,457.379	602.645	4.830
			602.645	1,457.379	3.012

Ordered as indicated by the arrow ($\downarrow$)