Display clutter is defined as an unintended effect of displaying visual imagery that may obscure or confuse other information, or that may be redundant or not relevant to the task at hand. There exists a limited amount of research that has explored both data-driven and knowledge-driven parameters as dual contributors to perceptions of clutter. In the present study, six pilots flew simulated approaches under varied workload conditions with synthetic and enhanced vision display configurations that represented “low,” “medium,” and “high” clutter. Results evinced that high clutter displays produced elevated reports of perceived clutter and workload due to density or redundant presentation of information, while low clutter displays were perceived as less cluttered but challenging to use because of a lack of information typically required for flight. Pilots identified both data-driven (bottom-up) and knowledge-driven (top-down) as contributors to clutter, and these challenges were mirrored in flight technical performance. Conclusions support the notion that design of advanced technologies must consider not only the physical appearance of data within the display, but also the utility of that information to tasks the displays are designed to support.