"Social Navigation" for the Web has been created as a response to the problem of disorientation in information space. It helps by visualizing traces of behavior of other users and adding social affordance to the information space. Despite the popularity of social navigation ideas, very few studies of social navigation systems can be found in the research literature. In this dissertation, I designed and carried out an experiment to explore the effect of several factors on social navigation support (SNS). The purpose of the experiment was to identify situations under which social navigation is most useful and to investigate the effect of personal factors, e.g., interpersonal trust, and gender on the likelihood of following social navigation cues. To gain a deeper insight into the effect of SNS on users' information seeking behavior, traditional evaluation methodologies were supplemented with eye tracking. The results of the study show that social navigation cues affect subjects' search behavior; specifically, while under time pressure subjects were more likely to use SNS. SNS was successful in guiding them to relevant documents and allowed them to achieve higher search performance. Reading abilities and interpersonal trust had a reliable effect on the SNS-following behavior and on subjects' subjective opinion about SNS. The effect of the gender was less pronounced than expected, contrary to the evidence in the literature. [The dissertation citations contained here are published with the permission of ProQuest LLC. Further reproduction is prohibited without permission. Copies of dissertations may be obtained by Telephone (800) 1-800-521-0600. Web page: http://www.proquest.com/en-US/products/dissertations/individuals.shtml.]