This text presents some methodological approaches to the gathering of information about the types of affect that emerge during cooperative interactions and which can influence subjects’ decisions and actions. Ways of accessing an affect differ according to the level of masking and reflection. Some types of affect are partially conspicuous and can be inferred through behavioural cues, such as linguistic and paralinguistic positioning of association-dissociation relative to a design proposal. Others are socially masked in order to avoid face-to-face confrontation and to allow an activity to continue. They can be verbalized in a second degree setting ; a case of interaction between an insurance agent and his clients, and a case of participative design meetings are developed to illustrate this point. This second degree setting must include specific techniques of questioning when effect is not easily verbalized because they are pre-reflected, i.e. not directly accessible to verbalization, and expert mediation is required to help this process. Some types of affect remain unconscious and inaccessible in a research interview. However, non-verbal signs may sometimes allow some hypothesis about their presence.