Analysing language development from a network approach

Children acquire their language in different ways. In this paper we propose some new measures from a network approach in quantifying these individual differences. Children's and care-takers' speech data are represented as a series of networks, word forms being taken as nodes and collocation of words as links. First, we compare two independent indices on network growth, including the size and the connectivity. Children with a small vocabulary (i.e. a small network size) may have more flexibility in word combination (i.e. a large connectivity), and vice versa. Second, we examine the changes of hub and authority nodes in the networks. The change in the roles of the two articles ";the" and "a" reflects the progress of syntactic development. While they constantly appear as authorities in adults' networks, the two articles often start in children's networks as hubs and shift to authorities later. Children shift by different routes and at different rates.