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Icon arrays use a matrix of icons (usually 100 or 1000 icons) to represent an at-risk population, simultaneously displaying both the number of expected events and the number of expected non-events. As a result, icon arrays have several advantages over simple numerical displays and other types of visual displays.

  • Icon arrays can be read simply by counting icons. This enables icon arrays to be more precisely read than bar or pie charts. Recent research suggests that counting icons is particularly common among more numerate readers.
  • Icon arrays show the part-whole relationship clearly in both relative count and relative area, thus embodying one of the advantages of pie charts and providing a significant advantage over bar charts and numerical representations.
  • Icon arrays are inherently a frequency-based representation of risk. Research by Gigerenzer, Peters and others has shown that many people, especially the less numerate, respond differently to frequency representations of risk than they do to percentages.
  • The icon arrays generated by Iconarray.com build the icons representing risk events from the bottom upwards by rows. As a result, these icon arrays have a rough height cue as well (displays of larger risks have colored icons rising higher than displays of lower risks), thus mirroring bar graphs in format as well.

Iconarray.com is a project of Brian J. Zikmund-Fisher, PhD, a decision psychologist and public health communications researcher who holds appointments as an Assistant Professor of Health Behavior and Health Education and Research Assistant Professor of Internal Medicine at the University of Michigan. Dr. Zikmund-Fisher also directs the Internet Survey lab at the UM Center for Bioethics and Social Sciences in Medicine (CBSSM), and is a core faculty member of the UM Risk Science Center.

Dr. Zikmund-Fisher uses his interdisciplinary background in decision psychology and behavioral economics to study factors that affect individual decision-making about a variety of health and medical issues. His research in health communications has involved the use of iterative experiments to develop and test methods for making risk statistics and other types of quantitative health information meaningful and useful for decision making by patients and the public. He has also researched the measurement of individual numeracy (people's ability to interpret quantitative health information) and the effects of low numeracy on people’s ability to understand risk. Other past research projects have included the National Survey of Medical Decisions (the DECISIONS study) and the National Institute for Environmental Health Sciences (NIEHS)-funded Community Perceptions of Dioxins (CPOD) Study that has used a mental models approach to examine how community residents are or are not able to interpret quantitative exposure information provided as part of exposure assessment studies. He also serves as an Associate Editor for the journal Medical Decision Making.

Development of clinician applications of Iconarray.com is being led by Holly O. Witteman, PhD. Dr. Witteman is a human factors engineer who completed a postdoctoral fellowship at the Center for Bioethics and Social Sciences in Medicine (CBSSM) at the University of Michigan, 2009-2011, and worked closely with Dr. Zikmund-Fisher on the design and development of Iconarray.com. She is currently an Assistant Professor of Medicine in the Office of Education and Continuing Professional Education and the Department of Family and Emergency Medicine in the Faculty of Health Sciences at Université Laval in Quebec City, Canada, and is also affiliated with the research center of the CHU de Québec, a large health care services network comprised of five teaching hospitals and four affiliated health care centers.

Dr. Witteman brings interdisciplinary training in mathematics, human factors engineering and social sciences to the study of technologies for risk communication and values clarification. She advocates reality-based design, which means designing for the way people are, not the way we wish they were. Her research addresses how people use online applications when making health decisions, how technologies can make risk numbers more meaningful for people, how tools might be designed and used to help clinicians and patients better understand and talk about risks and values, and how to better design these tools in ways that improve the user experience.

The following people provided substantial input into the design of iconarray.com or the earlier CBSSM pictograph generator:

  • Mark Dickson, MA (current lead developer)
  • Nicole L. Exe, MPH
  • Valerie Kahn, MPH
  • James Rampton, MPH/MSI candidate
  • Bob Burbach, BA
  • Jon Kulpa, BA/BS