With increased volume and sophistication of cyber attacks in recent years, maintaining situation awareness and effective task-prioritization strategy is critical to the task of cybersecurity analysts. However, high levels of mental-workload associated with the task of cybersecurity analyst's limits their ability to prioritize tasks. Task-prioritization is especially challenging in an environment consisting of unexpected changes in relative priority between various sub-tasks and workload. Cognitive-aids that provide predictions about potential threats are designed to guide attention towards unexpected shifts in priority or workload. However, cognitive-aids may not necessarily facilitate performance under high time-pressure. They may contribute to cognitive-load resulting from display complexity and information processing demand. The literature-review explores this issue from a Human Factors perspective, particularly taking into account previous work on attention-guidance, task-management, interruptions and workload-previews. A scaled-world simulation was built to emulate cyber-security monitoring and decision-making. An experiment involving 77 participants was conducted to examine the effectiveness of a Workload-Preview under differing task-load conditions on task-performance and task-prioritization in cyber-security monitoring. Based on literature, it was hypothesized that the presence of the Workload-Preview would facilitate Task-Performance and Task-Prioritization, especially under High Task-Load. Interestingly, experimental results do not support the hypotheses. Moreover, the Workload-Preview degraded Task-Prioritization of unexpected surges under High Task-Load. This appears to have been associated to the Workload-Preview contributing to increased mental-workload. The results of the study provide implications on factors that influence the effectiveness of cognitive-aids aimed at guiding attention and improving task-performance. [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.]