This paper draws on research from a wide literature base to develop a model relating Web navigation systems, disorientation, engagement, user performance, and intentions. The model is tested in an experimental study examining the effects of one simple and two global navigation systems. Although well-accepted design guidelines were followed for the first global navigation system, it was not superior to the simple system. However, the second global navigation system resulted in lower disorientation than the simple system. Based on the study's results, two design guidelines to govern the development of future Web-based systems are suggested. Readers need a sense of context, of their place within an organization of information. In paper documents this sense of "where you are" is a mixture of graphic and editorial organizational cues supplied by the graphic design of the book, the organization of the text, and the physical sensation of the book as an object. Electronic documents provide none of the physical cues we take for granted in assessing information. When we see a Web hypertext link on the page we have few cues to where we will be led, how much information is at the other end of the link, and exactly how the linked information relates to the current page. Even the view of individual Web pages is restricted for many users. (Lynch and Horton 2002) On IBM's website, the most popular feature was the search function, because the site was difficult to navigate. The second most popular feature was the "help" button, because the search technology was so ineffective. IBM's solution was a 10-week effort to redesign the site. ...In the first week after the redesign, use of the "help" button decreased 84 percent, while sales increased 400 percent. (UsabilityNet 2003)