I'd be really pleased if anybody helped me with some possible translation for the last sentence. Thanks.

1Representativeness The corpora that the list is based on should adequately represent the wide range of uses of language. In the past, most word lists have been based on written corpora. There needs to be a substantial spoken corpus involved in the development of a general service list. The spoken and written corpora used should also cover a range of representative text types. Biber's (1990) corpus studies have shown how particular language features cluster in particular text types. The corpora used should contain a wide range of useful types so that the biases of a particular text type do not unduly influence the resulting list.