Halliday & Matthiessen (1999: 84):
The most favoured 'band' in delicacy is that of the basic level: it is taxonomically most highly elaborated, it tends to be learnt first by children, and it construes categories with syndromes of usually salient functional and perceptual properties. … In addition, the "basic' degree in delicacy may have a special status in the instantiation of categories in text.In her study of lexicalisation in the pear stories, Downing (1980) found that the basic level was by far the most preferred one; these are the figures for concrete, nonhuman things (p. 106):
Such findings are interesting because they give some indication of what factors to consider in lexicalisation in text generation: a given phenomenon can, in principle, be construed at any point along the scale of delicacy. They are also interesting because they point to the relationship between the system and the instance: from the perspective of the system, we can observe that the basic degree of delicacy is most highly elaborated; from the perspective of the instance, we can observe that it is most frequent. However, we have to allow for considerable variation within a language — in particular, functional or registerial variation within the system according to the context of use, as in the variation between the spoken system of everyday life and the written system of science to which we turn next.