Table 2. Mean average precision for top 20 retrievals (weighted average 0.7-0.3).

Vocabulary size & features % used	50	100	200	400	600	800	1000	1200
10%	61.95	66.39	67.84	68.89	69.99	70.25	70.38	69.73
25%	62.45	66.86	67.56	67.73	70.2	71.2	70.6	70.21
50%	61.69	67.45	66.55	69.17	69.84	70.39	69.9	69.35
75%	62.03	66.49	67.24	69.84	69.65	70.5	70.15	70.01
100%	62.09	66.37	67.96	68.85	69.95	70.57	70.1	70.2
Mean	62.04	66.71	67.43	68.90	69.93	70.58	70.23	69.90
CI	±0.34	±0.57	±0.70	±0.95	±0.25	±0.45	±0.34	±0.45
Sigma	0.274	0.457	0.565	0.763	0.202	0.366	0.269	0.363