Do We Have Informational Services In Social Networks?: Analysis The Services Offered By Facebook And Twitter To The Services Of Digital Libraries

International audienceFacebook is a general social network, which allows registered Internet users to create their network: friendly, professional, family, etc. Twitter is a social network dedicated to micro-blogging, that is, the rapid exchange of information. Social networking sites are fast becoming one of the most popular tools for social interaction and information exchange. Previous research has shown a relationship between users' personalities and the use of their conveyed images and the emergence of fakenews. In addition, a preference for Facebook is often associated with the user's status (novice, general public, etc.) with personality differences such as journalists, politicians or academics, researchers who prefer (twitter) to disseminate information and news. Facebook is the dominant social network in terms of number of members, number of daily visitors and the number of exchanges it generates. It allows its users to connect with their acquaintances: whether professional, friendly, or other types. The goal of Facebook is to connect people with each other and allow them to interact around their personal social network. Twitter a social network dedicated to microblogging: users can communicate with each other through short messages no longer than 140 characters. The challenge here is to be aware of the information in real time and to react to it very quickly. This social network is enjoying worldwide and growing success in media ournalistic and political circles . Twitter and Facebook try to provide information and documentation services like digital libraries which are the permanent sources for scientific communities We will focus our assessment on macro criteria as essential: - ergonomics services, information retrieval services, personalized access services, documentation services, participatory services, networking service