MIT Press

Table 1

Effect of parameter setting on performances.

Parameter	Role of parameter	Effect on performance
W	window size	larger windows best suited to capture world-wide events
Δ	discretization size	larger discretization best suited to capture world-wide events
\|Σ\|	dimension of alphabet	larger alphabets positively affect purity, negatively affects recall
f	frequency threshold	higher frequency positively affects purity, negatively affects recall
δ	clustering parameter	higher values positively affect purity, negatively affect recall
τ	splitting parameter	higher values positively affect purity, negatively affect recall

Parameter	Role of parameter	Effect on performance
W	window size	larger windows best suited to capture world-wide events
Δ	discretization size	larger discretization best suited to capture world-wide events
\|Σ\|	dimension of alphabet	larger alphabets positively affect purity, negatively affects recall
f	frequency threshold	higher frequency positively affects purity, negatively affects recall
δ	clustering parameter	higher values positively affect purity, negatively affect recall
τ	splitting parameter	higher values positively affect purity, negatively affect recall