Perceptions of disease and risky behaviors are among the factors associated with health behaviors. The level of fear inspired by a particular condition or risk factor, as well as the sense of being informed about them, serve as valuable indicators in that, on the one hand, they rank risks in a way that is not necessarily consistent with their probability of occurrence or their proven danger, and on the other hand, they highlight potential gaps in public information. These representations are shaped in particular by individuals’ life experiences, their sociodemographic characteristics, and their exposure to information and prevention campaigns. They can also serve as an indicator of the public’s expectations regarding health. The concept of social representation is often used in the sense given to it by social psychology: for Denise Jodelet, it is a “socially constructed and shared form of knowledge, having a practical purpose and contributing to the construction of a reality common to a social group.” Laypeople’s representations play a practical role in that they constitute a coherent cognitive framework that gives meaning to each individual’s experience, and they can also serve as a guide for action. They constitute a particular type of knowledge, which has its own logic, generally distinct from scholarly logic. In theory, they rely on a capacity for articulation and justification, which is not the case in quantitative surveys where public perceptions are assessed through closed-ended questions. Thus, these are primarily estimators used to identify broad trends at the population level. Since 2000, the INPES Health Barometer has asked a series of questions about people’s sense of being informed on major health topics. The specific items asked in each survey wave have varied depending on current concerns, but the majority of them have remained the same from one wave to the next. Depression and cancer were introduced in 2005, new epidemics and Alzheimer’s disease in 2010, while questions on diet were discontinued in 2010, primarily due to concerns about the length of the questionnaire. Air and water pollution were replaced by a single, more generic item: “environment-related health risks.” A series of questions on fears regarding various risks or diseases has also been included in this survey since 2000. The wording explicitly invited respondents to describe their own situation regarding the risk or disease: “Among these various risks or diseases, please tell me if you fear them for yourself: not at all, a little, quite a bit, or a lot?” [excerpt from chapter]