The PAD scale, developed in 1974 by Albert Mehrabian and James Russell, is a tool for analyzing an individual’s emotional reactions to their environment across three dimensions: pleasure, arousal, and dominance. This scale consists of 18 items in the form of semantic differentials, with 6 for each dimension, evaluating a range from +4 to -4. Christian Derbaix and Ingrid Poncin highlight the common use of 18 semantic differentials, with 6 for each dimension, to implement the PAD. Some have also used the “circumcomplex model” to represent various emotions, focusing on pleasure and arousal. Furthermore, the Affect Grid, developed by Russell, Weiss, and Mendelsohn in 1989, offers a rapid method for assessing affect along the “pleasure-displeasure” and “arousal/arousal-apathy/deactivation” axes. This grid allows the respondent to rate the intensity of pleasure or displeasure horizontally and arousal vertically across nine levels ranging from high arousal to total apathy, for a total of 81 possibilities. This approach is particularly well-suited for capturing an overall reaction to a stimulus in a single instance, but it is not appropriate for continuous recording or repeated measurements at different points during the same consumption or exposure episode due to its complexity.