Large quantities of redundant clinical data are usually transferred from one clinical document to another, making the review of such documents cognitively burdensome and potentially error-prone. Inadequate designs of electronic health record (EHR) clinical document user interfaces probably contribute to the difficulties clinicians experience while processing patient-specific information during time-constrained patient encounters. Furthermore, the continuous need for clinicians to review multiple EHR clinical documents during the typical out-patient visit increases the likelihood of overloading their working memory in the short duration available for complex cognitive activities related to patient care. In a collection of three studies incorporating fundamental principles in clinical informatics, cognitive psychology and human-computer interaction, the think-aloud protocol, combined with other qualitative and quantitative methodologies, was utilized to investigate cognitive processes associated with clinicians' synthesis of EHR clinical documents, the impact of time restrictions on these processes, and implementing a novel visualization tool to enhance processing of these documents during patient care. These studies serve to fill fundamental knowledge gaps in our understanding of how clinicians interact with EHR systems when using clinical documents and can help future EHR system user interface design for clinical documentation with the ultimate goal of improving patient care and clinician satisfaction with these systems. [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.]