Table 4 

Number k discussion 

n 
document 
passage 
passage2 



Genomics 2007 
1 
0.3012 
0.0918 
0.1436 
5 
0.3349 
0.1400 
0.1588 

10 
0.3438 
0.1422 
0.1635 

20 
0.3438 
0.1422 
0.1635 

100 
0.3438 
0.1422 
0.1635 



Genomics 2006 
1 
0.3974 
0.1401 
 
5 
0.4049 
0.1445 
 

10 
0.4087 
0.1467 
 

20 
0.4083 
0.1466 
 

100 
0.4083 
0.1466 
 



Genomics 2005 
1 
0.3012 
 
 
5 
0.3116 
 
 

10 
0.3123 
 
 

20 
0.3123 
 
 

100 
0.3123 
 
 



Genomics 2004 
1 
0.3470 
 
 
5 
0.3555 
 
 

10 
0.3584 
 
 

20 
0.3584 
 
 

100 
0.3584 
 
 



HARD 2004 
1 
0.2015 
0.2005 
 
5 
0.2223 
0.2197 
 

10 
0.2250 
0.2208 
 

20 
0.2248 
0.2208 
 

100 
0.2248 
0.2208 
 



The number k is the parameter in the recursive reranking algorithm: (1) the empirical study makes a local optimization number k = 10 as the final depth in the final experiments; (2) k stands for the top k term associations weighted by the factor analysis based model; (3) the recursive reranking algorithm will rerank the baselines according to these k terms; (4) the more the results contain terms among these k terms, the higher ranking scores the results obtain; (5) five numbers such as 1, 5, 10, 20, 100, are tested; (6) five original baselines from our five data sets respectively, namely Genomics 2007, Genomics 2006, Genomics 2005, Genomics 2004 and HARD 2004; (7) k affects the performance greatly when k is smaller than 10, while the final performance almost has no change if k becomes larger than 10. 

Hu et al. BMC Bioinformatics 2012 13(Suppl 9):S2 doi:10.1186/1471210513S9S2 