Table 1 scheme of rating matrix R: TxP

From: Evaluating Rank-Coherence of Crowd Rating in Customer Satisfaction

Time P1 P2 Pj
t = 0 r(p0,1) Null  
t = 1 r(p1,1) r(p1,2)  
t = 2 r(p2,1) r(p2,2)  
t r(pt,1) r(pt,2) r(pt,j)