Concordance lines are a useful tool for investigating corpora, but their use is limited by the ability of the human observer to process information. Assessments of frequency and significance are difficult to make impressionistically, particularly in the case of very frequent words. Also, they are not particularly useful in collecting information about categories of things, such as ways of expressing future time, or the frequency of nominalisations, as opposed to words. In this chapter we look at methods of investigating corpora that go beyond concordance lines. These include statistical calculations of collocation and corpus annotation.

As suggested above, a distinction is made in this chapter between methods which are based on individual words and those which are based on categories. The final section in this chapter discusses the implications of the two approaches, making the point that what is at issue is not only methodology, but the theoretical presuppositions that lead to that methodology. Essentially, the word-based and the category-based approaches are used to answer different sets of questions, and may be evaluated in terms of the perceived usefulness of the questions. I shall stress that what is important is that anyone who uses commercially produced programs for exploiting corpora, or who reads about work in this area, should be aware of the assumptions behind the work, and the alternatives available.