Collocational information is not only useful, but also indispensable in many applications.
other definitions state explicitly that a collocation is an expression of language: "co-occurrence of two or more lexical items as realizations of structural elements within a given syntactic pattern" (Cowie, 1978); "a sequence of two or more consecutive words, that has characteristics of a syntactic and semantic unit" (Choueka, 1988).