In terms of the previous example, the aspect "speaker quality" should pay more attention on "lacking" and less attention on "like", compared with aspect "Mac OS" due to their different sentiment polarities.
for each aspect pair a i and a j in aspect list A, we compute the square loss on the coarse-grained attention vector a ca i and a ca j , and also estimate the distance d ij ∈ [0, 1] between a i and a j as the loss weight.