Structure and topic information in expository text overviews

The current wisdom on texts is that they should start by providing readers with an overview of the content (the topics discussed) and the structure (the relationship between the topics). However, in a recent paper Murray and McGlone (1997) reported that readers benefit from topic information but not from structural information provided in an overview of a very simple text. In the present experiments we ask whether these observations would be applicable to more complex texts in which structural information would be more important. Two experiments, which used a text with a complex hierarchical structure, replicated previous results on reading times. The second experiment also permitted us to rule out the effect of numerical signals in the text as the reason for the results.