By their very nature, Health Barometers are designed to be repeated over time, using the same methodologies and questionnaires, in order to track trends. As such, they are very useful tools for evaluating the initiatives implemented by public authorities. However, the 2008 Health and Nutrition Barometer was designed with the aim of refining certain elements to enhance its relevance. Consequently, the method for recording food consumption and the survey sample were modified for this third wave of the survey. Regarding the data collection method, since the first survey conducted in 1996, dietary intake had been recorded over the 24-hour period preceding the survey using a questionnaire in which foods were entered verbatim, as precisely as possible, by trained interviewers, followed by post-coding. In 2008, to optimize the efficiency and quality of data collection, it was decided to create a pre-coded list of foods in the form of a drop-down menu. This method is described in detail in the chapter “Data Collection Method and Food Categorization: Methodological Consistencies and Changes,” on page 65. During the development of this third wave of the survey, the relevance of the 24-hour recall compared to the frequency questionnaire was also called into question following an extensive literature review. It was nevertheless decided to prioritize the collection of data on foods consumed the previous day. The main argument was to ensure the tracking of trends, given that the historical perspective provided by the age of the first Health and Nutrition Barometer conducted in 1996 would constitute a major asset of this survey methodology. It was also this commitment to consistency in methodology that guided the decision to use telephone surveys, even though recent developments in telecommunications in France have led to significant adjustments, which will be described in detail in this chapter.[chapter excerpt]