Structure and access : the role of structural factors in text comprehension and information

In this thesis it is argued that structural factors play an important role in facilitating the access, comprehension, and recall of textual information, especially when the content of the material is unfamiliar to the reader. A study was made of the effects of manipulating text structure, familiarity of subjects with the text type, familiarity with the content, and instructions given to subjects, on comprehending and recalling information from scientific research reports. The results show that subjects familiar with the text type are able to make use of structure as an encoding strategy, and that the use of this structural strategy improves comprehension and recall when the content is unfamiliar. The study suggests that teaching readers to make use of structure in processing text can facilitate comprehension and recall. These results provide support for previous theories concerning the role of text structure, most of which has focused on narratives, to the neglect of research on expository prose. It is argued that some of the problems involved in the research using narratives, in particular, the problem of the lack of distinction between structural factors and more general knowledge of the content, may be obviated by research with other text types, such as the one used in this study. It is also argued that users of computer-based documentation systems need similar kinds of structural cues for accessing online information as they do for offline text comprehension and retrieval, and that the efficacy and type of such structural cues depends on several factors, such as the task requirement, as well the level of experience of the user. A second study examined the patterns of use of an online documentation system, and showed that users need different forms of organisation of the information as 'access structures, depending on different task requirements. Finally, proposals are made for improving the design of online documentation systems and for conducting future research into the needs of users of such systems.