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.