Causality scores depend on the number of occurrences that two terms t i and t j are in linguistic patterns known as causal cues (Chang and Choi, 2004) identifying precise cause/effect roles, e.g., "If...t i ..., then... t j ..." and "... t j ..., because...t i ...".
as more occurrences of (t i , t j ) in causal cues, its causality score is higher as: where f req(t i , t j ) is the frequency of observing the causal pair (t i , t j ) from an English corpus.