Even in adults, written production is still more costly than oral production

The aim of this research is to show that the mechanical demands of writing continue to affect the characteristics of produced texts in adults under certain situations of cognitive overload. The study reported here is intended to demonstrate that the quality of the text produced by educated adults falls when production is performed in the written rather than in the spoken mode, but only when the elements on the basis of which the texts are to be produced are difficult to relate to one another. In this view, we compared performance in a text production span task in either the oral or the written mode. This task consisted of presenting sets of words, semantically linked or not, from which adults had to produce texts including the words in the set. The results showed that neither the production mode nor the extent of the relationship between the items influenced the number of words recalled. By contrast, the number of ideas elaborated and the coherence of the produced texts are lower when the supplied items are difficult to link and when production is in the written mode. These results are interpreted in the framework of capacity theories in production. They suggest that the cost of managing written production is not always negligible in well-educated adults. When they have to produce texts on the basis of provided elements that are only weakly associated with one another in the written mode, the residual capacity necessary either to maintain and organise the information in working memory, or to adopt a strategic approach to the composition of the texts, is insufficient because the cost of this elaboration must be added to that of the management of the written production.