As part of the preparation for this third wave of the survey and with a view to improvement, several aspects of the data collection method used in previous waves of the survey were discussed and evaluated, leading to decisions to retain, modify, or supplement them. First, the advantages, disadvantages, and feasibility of several dietary data collection methods were analyzed. The following options were weighed against one another: the method used until then of a single 24-hour recall, conducting multiple 24-hour recalls, quantifying food intake, and opting for a frequency questionnaire. An extensive review of the literature, elements of which are presented here, made it possible to evaluate the arguments in favor of selecting the survey method to be used for this third wave. The ability to measure changes in dietary behaviors over a twelve-year period ultimately led to the decision to maintain the data collection method used since 1996: a semi-quantitative 24-hour recall. Once this choice was made, considerations drawn from the sociological literature led us to reflect on how to improve the quality of data derived from a 24-hour recall. The objective was to encourage respondents to clearly distinguish between dietary norms and reported dietary practices. As we will see at the beginning of this chapter, changes to the questionnaire’s preliminary instructions allowed for significant methodological improvements in this regard. Furthermore, more operational objectives led us to reevaluate the type of food coding used up to that point. For recording foods consumed the previous day, a pre-coding system, using a pre-coded list of foods, was thus implemented. The choice of computer-automated data collection was motivated by the goal of increasing efficiency compared to the post-coding of foods entered in plain text, as practiced in previous waves of the survey. The operation of this data entry method will be described in a second section presenting the food collection methods. The main principles of the 24-hour recall will be briefly reviewed, followed by a presentation of the structure and technical details of the data collection method implemented for this 2008 Health and Nutrition Barometer. Finally, a review of the content of the food categories selected in 1996 and 2002 led to slight modifications in the classification of certain foods, with the aim of improving it. The details of these modifications and the analysis of trends, using the same categorization, will be presented at the end of the chapter.[chapter introduction]