A well-designed social platform has the potential to reduce senior isolation and promote active ageing. However, to design tools that respond to the user need it is important to understand what types of seniors will use it and what are their needs. Through a user-oriented approach at several design stage: focus group, co-creation and usability test we were able to identify the different roles related to the use of the platform, which allowed us to classify them by type, each type having very specific needs. Among the types of users identified, "Active users" are looking for an efficient platform. "Socialiser users" are more passive and mainly interested to participate in activities and are sensitive to trust. "Low skilled users" have limited digital skills and must be accompanied to start with the platform. Finally, "Sporadic users" lack of time to actively use the platform but would use a platform involving a large number of stakeholders. It is important to include all these different types of users in the design phase to ensure the future success of the social platform.
Keywords: Aged; needs assessment; social media; social participation; user-computer interface.