BioVis 2016 Design Contest CFP*Motivation* Many decisions on uncertain events are made based on the likelihood inferred from data of limited validity. The uncertainty is often expressed in numerical form as frequencies or probabilities. However, they are notoriously difficult to communicate effectively. Studies have shown both laymen and professionals have trouble understanding risk information involving conditional probabilities and Bayesian reasoning [1-6, 9]. *Contest Challenge* *This year’s design contest focuses on the visual communication of conditional probabilities, such as the communication of risk.* The contest is aimed at the exploration of the visual representations to communicate, or to support the communication of, risks in Bayesian reasoning tasks. Previous studies have found that the ability of people to solve Bayesian problems depends on the way the information is conveyed [2]. In this contest, a special emphasis is laid on the design of visual aids. For this challenge, we picked two Bayesian reasoning tasks: the classic mammography problem [3] and an example from a prenatal test brochure for Down Syndrome [2]. Participants are asked to design visual solutions for both tasks. We supply a scenario to provide a context to design your visual solutions, and a text and a target question for each task. Consider following questions: - What does it mean to have a positive test result in a screening test? - What is the best way to communicate a test result so a patient will understand it? - For the second task, consider how the prevalence (epidemiological parameters) affects the predictive power of the screening test. *Submission deadline:* *September 23, 2016*. *Accepted entries will be asked to present during the poster session of BioVis at the IEEE VIS conference (October 24th, 2016).* For further information, please refer to the BioVis 2016 design contest webpage at: http://biovis.net/2016/designContest_vis/