Designing an effective link structure for customer interfaces is critical for the success of cyber shopping malls. The link structure comprises various types of links that connect a hypertext page with other pages. Links can be classified as either basic links based on the structure of the malls or add-on links to provide additional paths. Providing appropriate add-on links is essential for the convenience of navigation in a mall. This study focuses on the relation between the links and mental model, and maintains that combinations of add-on links according to the mental model of customers will increase the convenience and pleasure of cyber shopping. For the study, add-on links were classified into Next-To-Peer (NTP) links, Up-To-Parent (UTP) links, and Up-To-Top (UTT) links, and eight different versions of experimental malls were constructed according to the combination of three add-on links. One hundred and seventy four subjects participated in the experiment, performed nine shopping tasks, and were measured in terms of the rate of add-on links recalled and the convenience of navigation. The result of the experiment shows that the rate of recalled links has a significant relation to the convenience of navigation, although the convenience of navigation does not increase linearly with the number of add-on links in a cyber shopping mall. To construct the optimal add-on navigation structure, it is essential to construct links that fit customers' mental models.

Link structure; add-on links; NTP; UTP; UTT; mental model