Learning to identify referents

When do children intentionally use the indefinite article to identify referents for their listener? Children between five and eight years of age were presented with a communication task under four different experimental conditions, in an attempt to find contexts which would encourage the appropriate use of such indefinite expressions. Even the eight year olds failed to identify their referents consistently, although nearly all the children used indefinite expressions intermittently when mentioning new referents. The results are interpreted in terms of the complexity of the task and the children's motivation to communicate.