Education policy in the United States centers K-12 assessment efforts primarily on standardized tests. However, such tests may not provide an accurate and reliable representation of what students understand about the complexity of science. Research indicates that students tend to pass science tests, even if they do not understand the concepts being assessed. On standardized tests, such concepts are typically assessed via multiple-choice questions, which may check student receptive understanding of science-related vocabulary terms rather than their ability to develop hypotheses and design experiments to test those hypotheses. In an attempt to address these assessment issues, our SAVE Science project has been exploring the use of immersive virtual environments as platforms for both learning and assessment. SAVE Science (Situated Assessment in Virtual Environments for Science Content and Inquiry) is an NSF-funded study exploring the use of virtual world-based tests to assess the science knowledge and skill of middle school students. The main goal of SAVE Science is to explore the value of virtual world-based assessments as supplements or alternatives to more traditional forms of assessment. In pursuit of that goal, we are examining design frameworks designed to help students manage the high cognitive load they may experience while completing the tests. In this paper, we present results from a study exploring the use of visual signaling techniques in virtual world-based assessments, with a particular focus on their use and impact in visually complex, high visual search environments. The study focused on the use of visual signaling to reduce perceived student cognitive load, while simultaneously increasing the number of interactions students perform with assessment-relevant objects in a virtual world (assessment efficiency).