The Internet takes a more and more important role for accessing information. But if all that content is not accompanied by organization it won't be of much help. The way we organize information defines the way we understand it. Hence how to provide information efficiently in this complex net of information has been one of the most important fields in Human Computer Interaction.
In this research a three-dimensional conceptual model was proposed which represents the underpinning cognitive attributes which should be embedded in information structure design. The model consists of task types, familiar with the information structure and individual cognitive style differences.
Two studies were conducted to test the model. The first one investigated how to design the information structures under different conditions in an information retrieval application. Hierarchical and network structures were of particular interest. Six experiments were designed to probe the issues of task types (exploratory vs.browsing); information nature (science knowledge vs. non-science knowledge) and whether users are clear about the information structure or not, which may affect efficiency of information retrieval using hierarchical or network structure. The second investigated the information structure design from the individual difference viewpoint.
The data in first study were reanalyzed according to participants' different time cognitive styles. The purpose of this study is to probe whether individual users have different information structure and how to design information structures for individual users under different conditions.
The laboratory experiments, usability testing and questionnaire were used in this research. Main conclusions of this research are as follows:
1) The task type affects .the information structures on the efficiency of browsing task participants of the network structure performed better than those of the hierarchical structure.
2) Whether users are aware of the information structure or not affects the information structures on the efficiency of information retrieval. When users are aware of the information structures the network structure benefits the efficiency of information retrieval.
3) Different individuals have different information organization structures. Individuals' time cognitive style affect information structures on the efficiency of information retrieval. It will benefit the efficiency of information retrieval to design the information structures based on user individual cognitive styles.