CALIDAD DEL AIRE Y MEDIO AMBIENTE INDUSTRIAL

The 1970s and early 1980s witnessed an intensive scrutiny of the processes of mother-tongue language acquisition in English. There is space in this section to do no more than isolate some main trends in the research with specific reference to vocabulary development in the pre-school phase. The attempt to describe what is specifically semantic in that development should reveal that easy distinctions between syntactic, semantic and pragmatic features are not possible. Important questions concerning the relations between linguistic and cognitive development as well as arguments concerning the relative primacy of concept formation and linguistic identification can be found in relevant surveys and discussions in Fletcher and Garman (1979), Elliot (1981), Kates (1980, Ch. 3) and Lock and Fisher (1984). Three main bodies of research will be briefly reviewed: Clark’s semantic-feature acquisition hypothesis; Nelson’s functional core concept; and Bowerman’s research into semantic prototypes.

Clark (1973) stresses the role of perceptual information in a child’s tic representation of words. Her view is that a word possesses a set of seman-tic features but that children initially assign meanings on the basis of what they encode to be a word’s prominent perceptual characteristics. Thus, a ball may be primarily distinguished as being round, as opposed to soft, yellow or squashy or that it can bounce or roll – all less perceptually prominent features which may be, of course, subsequently acquired. The basis of Clark’s semantic-feature acquisition hypothesis is thus one of perceptual primacy and it provides an explanation for the commonly observed characteristic of overextension. Overextensions result when the child uses a semantic feature to generalize to other objects. For example, a child might refer to an apple or a door-knob as a ball, or overextend the meaning of the utterance tick-tock (meaning ‘clock’) to watches, the dials of a weighing machine, a cooker or a TV set. Table 7.1, adapted from Clark (1973), illustrates the hypothesis further. See Clark (1993) for more recent extensions of this work.

In contrast to Clark’s assignment of primacy to perceptual features, Nelson (1974) proposes that the concept underlying the distinction made by the child may be formed according to the functions or actions associated with the object. In other words, in the case of ball the essential semantic core is not 180 Learning and teaching vocabulary

that it is perceived as round but that it functions in a particular way as a result of the way the child interacts, or engages in activity with the ball. What is important, therefore, is what an object does or what a child can do with or to it. Nelson puts it as follows:

The child focusses his attention for the first time on a ball which his mother picks up and bounces across the living room carpet. He rolls it back to her. The particular actions he and his mother are engaged in change from time to time. (He may throw the ball, it may get lodged under the sofa or even knock over and break something.) The ball, however, is a constant factor and the child’s concept of ball depends on his interaction with it, not upon verbal cues such as his mother saying

‘This is a ball.’

(Nelson, 1974, p. 277) Nelson cites interesting supporting evidence for her view in that it is rare for children to have in their initial lexicon items which regularly surround the child, like items of furniture; more likely to be present will be items like spoon, shoe and doll with which he or she has regular action-based encounters.

Nelson’s functional core concept does not invalidate the property of over-extension or underover-extension;¹ it simply approaches the semantic attributes of words from a different perspective.

Although more research is required, it is reasonable to conclude that perceptual and functional criteria play an important part in early lexical acquisition, at least as far as reference to objects is concerned. We should, Table 7.1 Examples of new terms and overextensions in L1 acquisition

Perceptual dimension

Language being learned

Child’s form

First referent

Overextensions

shape English bird sparrows cows, dogs, cats, any

animal moving shape English kotibaiz bars of cot large toy abacus,

toast-rack with parallel bars, picture of building with columns

sound Russian dany sound of bell clock, telephone,

door-bells

taste French cola chocolate sugar, tarts, grapes,

figs, peaches touch Russian va white plush dog muffler, cat, father’s

fur coat Source: Clark, 1973.

however, note in this respect work on semantic prototypes by Bowerman (1978) which challenges a basic assumption of Clark and Nelson. For Bowerman, no set of features nor any single semantic core determines the meaning acquisition of particular words. For example, Bowerman’s daughter’s use of kick first occurred when she propelled a ball forward with her foot. Subsequently, she used kick in the following situations: when she kicked an immovable floor fan, when she pushed her stomach against a mirror or a sink, at the sight of an object being propelled, as when she moved a ball with the wheel of a tricycle, at the movement of a moth fluttering on a table, and for the action of cartoon tortoises kicking their legs in the air. Bowerman argues that for her daughter kick involved waving limbs, sudden sharp contact with an object and an act of propulsion but that it was not possible to isolate similarities between features or to determine which particular feature(s) is critical or ‘prototypical’.

Bowerman’s research at least demonstrates clearly the kinds of combin-ations of features which have to be acquired by a child before they can be said to have appropriated the semantics of the adult use of a word but the investigations reported here raise further problems and questions. First, how appropriate is it to see the child’s lexicon as simply an incomplete version of the adult’s, and to what extent does such a pre-theoretical assumption condition the interpretations made by adults of the ‘meanings’ children produce? And can the possibility of metaphoric uses by children be discounted (e.g. Gardner et al., 1975; see also Elliot, 1981, pp. 85–90; and Winner, 1988)? Secondly, is it feasible to analyse children’s lexical acquisition in isolation from a parallel analysis of the situational and communicative contexts in which the words are used and, if so, then what kind of taxonomy of contexts would be necessary? Thirdly, what is the relationship between production and comprehension of the meanings of words, how might this affect processes of ‘extension’ and what explanatory potential might such a relationship have for examining the primacy of mental representation over linguistic representation of objects? Fourthly, how far is it realistic to isolate semantic development, as we are in fact doing here, from the acquisition of the syntactic and discoursal meanings of words? Is word-meaning based on semantic properties which are somehow intrinsic to the words, or do mean-ings emerge, as Halliday (1975) argues, as a result of a structuring by the child of words in relation to other words within an overall scheme of functions which are social, interpersonal and individual in their linguistic realization (see also Grieve and Hoogenraad, 1979)? And, finally, examination of the linguistic and communicative interrelations of meanings highlights the acquisition of non-referential items such as prepositions, grammatical words, comparatives, etc. – all of which are part of the acquisition of a lexicon.

Interesting recent research into lexical acquisition in one-year-olds questions the relationship between the performance of an action and the naming of an object which is central to most theories in the 1970s (cf. Schwartz, 1983); and studies of mother–child interaction with one-year-old subjects conclude that 182 Learning and teaching vocabulary

the way mothers regulate and maintain interaction can systematically in flu-ence the development of personal–social words before that of object labels (see Tomasello and Todd, 1983).