The purpose of this mixed methods study was to investigate the role that background knowledge, critical evaluation of information, and a reader's dispositions play in predicting online reading comprehension performance, during comprehension tasks that take place in either less restricted or more restricted information spaces. Sequential regression models demonstrated that, after controlling for verbal intelligence, critical evaluation and prior knowledge were significant in both the less restricted information space and the more restricted information space. Scores on a disposition measure were only significant in the more restricted model. Qualitative analysis, using verbal protocol methods, found that were key overall differences in how skilled online readers navigate and monitor meaning during Internet inquiry tasks. Skilled readers engage in strategic text assembly. However all participants were not successful at evaluating or communicating online information. The results of this study contribute to both research and practice. For research, the results inform richer and more complex models of online reading comprehension. For practice, the results inform teachers charged with teaching literacy in a constantly evolving world, one in which the Internet is increasingly important to both reading and learning. [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.bibliotheek.ehb.be/en-US/products/dissertations/individuals.shtml.]